diff --git a/.github/workflows/skyeye.yaml b/.github/workflows/skyeye.yaml
index cb470bac..266efa44 100644
--- a/.github/workflows/skyeye.yaml
+++ b/.github/workflows/skyeye.yaml
@@ -133,6 +133,9 @@ jobs:
             mingw-w64-ucrt-x86_64-go
             mingw-w64-ucrt-x86_64-curl
             zip
+      - name: Download Go modules
+        shell: msys2 {0}
+        run: GOMODCACHE=$(cygpath -w /ucrt64/pkg/mod) go mod download
       - name: Build Skyeye
         shell: msys2 {0}
         run: make skyeye.exe
diff --git a/Makefile b/Makefile
index 7cd0b02a..087438cc 100644
--- a/Makefile
+++ b/Makefile
@@ -41,7 +41,8 @@ SKYEYE_BIN = skyeye.exe
 SKYEYE_SCALER_BIN = skyeye-scaler.exe
 # Override Windows Go environment with MSYS2 UCRT64 Go environment
 GO = /ucrt64/bin/go
-GOBUILDVARS += GOROOT="/ucrt64/lib/go" GOPATH="/ucrt64"
+GOMODCACHE_NATIVE := $(shell cygpath -w /ucrt64/pkg/mod)
+GOBUILDVARS += GOROOT="/ucrt64/lib/go" GOPATH="/ucrt64" GOMODCACHE="$(GOMODCACHE_NATIVE)"
 # On Windows, we statically link opus and soxr so users don't need to install them.
 LIBRARIES = opus soxr
 CFLAGS = $(shell pkg-config $(LIBRARIES) --cflags --static)
@@ -49,8 +50,12 @@ BUILD_VARS += CFLAGS='$(CFLAGS)'
 EXTLDFLAGS = -Wl,-Bstatic $(shell pkg-config $(LIBRARIES) --libs --static) -Wl,-Bdynamic
 LDFLAGS += -linkmode external -extldflags "$(EXTLDFLAGS)"
 # On Windows, we copy the ONNX Runtime DLLs so we can package them with the binary during distribution.
-SHERPA_DLL_DIR := $(shell $(GOBUILDVARS) $(GO) list -m -json github.com/k2-fsa/sherpa-onnx-go-windows 2>/dev/null | grep '"Dir"' | cut -d'"' -f4)/lib/x86_64-pc-windows-gnu
+# The module version is read directly from go.mod to avoid invoking Go (which would trigger
+# toolchain delegation to a Windows-native binary that misinterprets MSYS2 POSIX paths).
+SHERPA_VERSION := $(shell grep 'k2-fsa/sherpa-onnx-go-windows' go.mod | awk '{print $$2}')
+SHERPA_DLL_DIR := /ucrt64/pkg/mod/github.com/k2-fsa/sherpa-onnx-go-windows@$(SHERPA_VERSION)/lib/x86_64-pc-windows-gnu
 SHERPA_DLLS = sherpa-onnx-c-api.dll onnxruntime.dll sherpa-onnx-cxx-api.dll
+BUILD_VARS += SHERPA_DLL_DIR="$(SHERPA_DLL_DIR)"
 endif
 
 BUILD_VARS += LDFLAGS='$(LDFLAGS)'
diff --git a/internal/application/compose.go b/internal/application/compose.go
index ee120e57..c739fae0 100644
--- a/internal/application/compose.go
+++ b/internal/application/compose.go
@@ -52,7 +52,7 @@ func (a *Application) composeCall(ctx context.Context, call any, out chan<- Mess
 		response = a.composer.ComposeShoppingResponse(c)
 	case brevity.SnaplockResponse:
 		response = a.composer.ComposeSnaplockResponse(c)
-	case brevity.SpikedResponseV2:
+	case brevity.SpikedResponse:
 		response = a.composer.ComposeSpikedResponse(c)
 	case brevity.StrobeResponse:
 		response = a.composer.ComposeStrobeResponse(c)
diff --git a/internal/application/synthesize.go b/internal/application/synthesize.go
index ac0268b4..393d4594 100644
--- a/internal/application/synthesize.go
+++ b/internal/application/synthesize.go
@@ -41,7 +41,7 @@ func (a *Application) synthesizeMessage(ctx context.Context, response composer.N
 	start := time.Now()
 	synthesisCtx, synthesisCancel := context.WithTimeout(ctx, 30*time.Second)
 	defer synthesisCancel()
-	audio, err := a.speaker.SayContext(synthesisCtx, response.Speech)
+	audio, err := a.speaker.Say(synthesisCtx, response.Speech)
 	if err != nil {
 		log.Error().Err(err).Msg("error synthesizing speech")
 		a.trace(traces.WithRequestError(ctx, err))
diff --git a/pkg/brevity/spiked.go b/pkg/brevity/spiked.go
index 4b168e57..f6b41183 100644
--- a/pkg/brevity/spiked.go
+++ b/pkg/brevity/spiked.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 
 	"github.com/dharmab/skyeye/pkg/bearings"
-	"github.com/martinlindhe/unit"
 )
 
 // SpikedRequest is a request to correlate a radar spike within ±30 degrees.
@@ -22,32 +21,7 @@ func (r SpikedRequest) String() string {
 
 // SpikedResponse reports any contacts within ±30 degrees of a reported radar spike.
 // Reference: ATP 3-52.4 Chapter V section 13.
-//
-// Deprecated: Use SpikedResponseV2 instead.
 type SpikedResponse struct {
-	// Callsign of the friendly aircraft calling SPIKED.
-	Callsign string
-	// True if the spike was correlated to a contact. False otherwise.
-	Status bool
-	// Range to the correlated contact. If Status is false, this may be 0.
-	Range unit.Length
-	// Altitude of the correlated contact. If Status is false, this may be 0.
-	Altitude unit.Length
-	// Aspect of the correlated contact. If Status is false, this may be UnknownAspect.
-	Aspect Aspect
-	// Track of the correlated contact. If Status is false, this may be UnknownDirection.
-	Track Track
-	// Declaration of the correlated contact. If Status is false, this may be Clean.
-	Declaration Declaration
-	// Number of contacts in the correlated group. If Status is false, this may be zero.
-	Contacts int
-	// Reported spike bearing. This is used if the response did not correlate to a group.
-	Bearing bearings.Bearing
-}
-
-// SpikedResponseV2 reports any contacts within ±30 degrees of a reported radar spike.
-// Reference: ATP 3-52.4 Chapter V section 13.
-type SpikedResponseV2 struct {
 	// Callsign of the friendly aircraft calling SPIKED.
 	Callsign string
 	// Reported spike bearing. This is used if the response did not correlate to a group.
diff --git a/pkg/composer/spiked.go b/pkg/composer/spiked.go
index d070d9ad..f6a08d54 100644
--- a/pkg/composer/spiked.go
+++ b/pkg/composer/spiked.go
@@ -5,6 +5,6 @@ import (
 )
 
 // ComposeSpikedResponse constructs natural language brevity for responding to a SPIKED call.
-func (c *Composer) ComposeSpikedResponse(response brevity.SpikedResponseV2) NaturalLanguageResponse {
+func (c *Composer) ComposeSpikedResponse(response brevity.SpikedResponse) NaturalLanguageResponse {
 	return c.composeCorrelation("spike", response.Callsign, response.Status, response.Bearing, response.Group)
 }
diff --git a/pkg/controller/spiked.go b/pkg/controller/spiked.go
index 8cbca07e..7ce007dc 100644
--- a/pkg/controller/spiked.go
+++ b/pkg/controller/spiked.go
@@ -14,7 +14,7 @@ func (c *Controller) HandleSpiked(ctx context.Context, request *brevity.SpikedRe
 	if correlation.Callsign == "" {
 		c.calls <- NewCall(ctx, brevity.NegativeRadarContactResponse{Callsign: request.Callsign})
 	} else {
-		response := brevity.SpikedResponseV2{
+		response := brevity.SpikedResponse{
 			Callsign: correlation.Callsign,
 			Status:   correlation.Group != nil,
 			Bearing:  correlation.Bearing,
diff --git a/pkg/encyclopedia/aircraft.go b/pkg/encyclopedia/aircraft.go
index 998e0b43..3becd980 100644
--- a/pkg/encyclopedia/aircraft.go
+++ b/pkg/encyclopedia/aircraft.go
@@ -2,7 +2,6 @@
 package encyclopedia
 
 import (
-	"slices"
 	"time"
 
 	"github.com/dharmab/skyeye/pkg/brevity"
@@ -89,13 +88,6 @@ func (a Aircraft) HasTag(tag AircraftTag) bool {
 	return ok && v
 }
 
-// HasAnyTag returns true if the aircraft has any of the specified tags.
-//
-// Deprecated: Use slices.Contains instead.
-func (a Aircraft) HasAnyTag(tags ...AircraftTag) bool {
-	return slices.ContainsFunc(tags, a.HasTag)
-}
-
 // ThreatRadius returns the aircraft's threat radius.
 func (a Aircraft) ThreatRadius() unit.Length {
 	if a.threatRadius != 0 || a.HasTag(Unarmed) {
diff --git a/pkg/radar/group.go b/pkg/radar/group.go
index f864985f..e26e9576 100644
--- a/pkg/radar/group.go
+++ b/pkg/radar/group.go
@@ -75,7 +75,7 @@ func (g *group) altitudes() []unit.Length {
 
 // circularMean computes the circular mean of all contacts' courses.
 // Returns the mean magnetic bearing and a coherence value in range 0-1.
-// 0 means no coherence, 1 means all courses are prefectly coherent.
+// 0 means no coherence, 1 means all courses are perfectly coherent.
 func (g *group) circularMean() (bearings.Bearing, float64) {
 	var sumOfSines, sumOfCosines float64
 	for _, tf := range g.contacts {
diff --git a/pkg/recognizer/parakeet/generate_windows.go b/pkg/recognizer/parakeet/generate_windows.go
index a009f564..9ecce6e6 100644
--- a/pkg/recognizer/parakeet/generate_windows.go
+++ b/pkg/recognizer/parakeet/generate_windows.go
@@ -2,4 +2,4 @@
 
 package parakeet
 
-//go:generate sh -c "SHERPA_LIB=$(go list -m -json github.com/k2-fsa/sherpa-onnx-go-windows 2>/dev/null | grep '\"Dir\"' | cut -d'\"' -f4)/lib/x86_64-pc-windows-gnu && cd \"$SHERPA_LIB\" && gendef sherpa-onnx-c-api.dll && dlltool -d sherpa-onnx-c-api.def -l libsherpa-onnx-c-api.dll.a && gendef onnxruntime.dll && dlltool -d onnxruntime.def -l libonnxruntime.dll.a && gendef sherpa-onnx-cxx-api.dll && dlltool -d sherpa-onnx-cxx-api.def -l libsherpa-onnx-cxx-api.dll.a"
+//go:generate sh -c "cd \"$SHERPA_DLL_DIR\" && gendef sherpa-onnx-c-api.dll && dlltool -d sherpa-onnx-c-api.def -l libsherpa-onnx-c-api.dll.a && gendef onnxruntime.dll && dlltool -d onnxruntime.def -l libonnxruntime.dll.a && gendef sherpa-onnx-cxx-api.dll && dlltool -d sherpa-onnx-cxx-api.def -l libsherpa-onnx-cxx-api.dll.a"
diff --git a/pkg/simpleradio/message.go b/pkg/simpleradio/message.go
index b5c7bd6b..2e3d30b9 100644
--- a/pkg/simpleradio/message.go
+++ b/pkg/simpleradio/message.go
@@ -34,7 +34,8 @@ func (c *Client) newMessage(t types.MessageType) types.Message {
 		Version: "2.1.0.2", // stubbing fake SRS version, TODO add flag
 		Type:    t,
 	}
-	message.Client = c.clientInfo
+	client := c.clientInfo
+	message.Client = &client
 	return message
 }
 
@@ -51,14 +52,16 @@ func (c *Client) handleMessage(message types.Message) {
 		logMessageAndIgnore(message)
 	case types.MessageSync:
 		c.syncClients(message.Clients)
-	case types.MessageUpdate:
-		c.syncClient(message.Client)
-	case types.MessageRadioUpdate:
-		c.syncClient(message.Client)
+	case types.MessageUpdate, types.MessageRadioUpdate:
+		if message.Client != nil {
+			c.syncClient(*message.Client)
+		}
 	case types.MessageClientDisconnect:
-		c.removeClient(message.Client)
+		if message.Client != nil {
+			c.removeClient(*message.Client)
+		}
 	case types.MessageExternalAWACSModePassword:
-		if message.Client.Coalition == c.clientInfo.Coalition {
+		if message.Client != nil && message.Client.Coalition == c.clientInfo.Coalition {
 			log.Debug().Any("remoteClient", message.Client).Msg("received external AWACS mode password message")
 			// TODO is the update necessary?
 			if err := c.updateRadios(); err != nil {
diff --git a/pkg/simpleradio/types/message.go b/pkg/simpleradio/types/message.go
index 94457b51..0746931d 100644
--- a/pkg/simpleradio/types/message.go
+++ b/pkg/simpleradio/types/message.go
@@ -21,7 +21,7 @@ type Message struct {
 	// Version is the SRS client version.
 	Version string `json:"Version"`
 	// Client is used in messages that reference a single client.
-	Client ClientInfo `json:"Client"` // TODO v2: Change type to *ClientInfo and set omitempty
+	Client *ClientInfo `json:"Client,omitempty"`
 	// Clients is used in messages that reference multiple clients.
 	Clients []ClientInfo `json:"Clients,omitempty"`
 	// ServerSettings is a map of server settings and their values. It sometimes appears in Sync messages.
diff --git a/pkg/synthesizer/speakers/macos.go b/pkg/synthesizer/speakers/macos.go
index 70272917..7dd3e38c 100644
--- a/pkg/synthesizer/speakers/macos.go
+++ b/pkg/synthesizer/speakers/macos.go
@@ -50,8 +50,8 @@ func NewMacOSSpeaker(useSystemVoice bool, playbackSpeed float64) Speaker {
 	return synth
 }
 
-// SayContext implements [Speaker.SayContext].
-func (s *macOSSynth) SayContext(ctx context.Context, text string) ([]float32, error) {
+// Say implements [Speaker.Say].
+func (s *macOSSynth) Say(ctx context.Context, text string) ([]float32, error) {
 	outFile, err := os.CreateTemp("", "skyeye-*.aiff")
 	if err != nil {
 		return nil, fmt.Errorf("failed to create temporary AIFF file: %w", err)
@@ -86,8 +86,3 @@ func (s *macOSSynth) SayContext(ctx context.Context, text string) ([]float32, er
 	f32le := pcm.S16LEBytesToF32LE(sample)
 	return f32le, nil
 }
-
-// Say implements [Speaker.Say].
-func (s *macOSSynth) Say(text string) ([]float32, error) {
-	return s.SayContext(context.Background(), text)
-}
diff --git a/pkg/synthesizer/speakers/piper.go b/pkg/synthesizer/speakers/piper.go
index 1232b293..29584114 100644
--- a/pkg/synthesizer/speakers/piper.go
+++ b/pkg/synthesizer/speakers/piper.go
@@ -37,8 +37,8 @@ func NewPiperSpeaker(v voices.Voice, playbackSpeed float64, playbackPause time.D
 	return &piperSynth{tts: tts, speed: playbackSpeed, pauseLength: playbackPause}, nil
 }
 
-// SayContext implements [Speaker.SayContext].
-func (s *piperSynth) SayContext(_ context.Context, text string) ([]float32, error) {
+// Say implements [Speaker.Say].
+func (s *piperSynth) Say(_ context.Context, text string) ([]float32, error) {
 	synthesized, err := s.tts.Synthesize(text, piper.WithSpeed(float32(s.speed)), piper.WithPause(float32(s.pauseLength.Seconds())))
 	if err != nil {
 		return nil, fmt.Errorf("failed to synthesize text: %w", err)
@@ -50,8 +50,3 @@ func (s *piperSynth) SayContext(_ context.Context, text string) ([]float32, erro
 	f32le := pcm.S16LEBytesToF32LE(downsampled)
 	return f32le, nil
 }
-
-// Say implements [Speaker.Say].
-func (s *piperSynth) Say(text string) ([]float32, error) {
-	return s.SayContext(context.Background(), text)
-}
diff --git a/pkg/synthesizer/speakers/speaker.go b/pkg/synthesizer/speakers/speaker.go
index 84a11f5a..10585fba 100644
--- a/pkg/synthesizer/speakers/speaker.go
+++ b/pkg/synthesizer/speakers/speaker.go
@@ -14,10 +14,7 @@ import (
 // Speaker provides text-to-speech.
 type Speaker interface {
 	// Say returns F32LE PCM audio for the given text.
-	//
-	// Deprecated: Use SayContext instead.
-	Say(string) ([]float32, error)
-	SayContext(context.Context, string) ([]float32, error)
+	Say(context.Context, string) ([]float32, error)
 }
 
 func downsample(sample []byte, sourceRate unit.Frequency) ([]byte, error) {
diff --git a/pkg/trackfiles/trackfile_test.go b/pkg/trackfiles/trackfile_test.go
index 19f0f95d..76be72d9 100644
--- a/pkg/trackfiles/trackfile_test.go
+++ b/pkg/trackfiles/trackfile_test.go
@@ -69,7 +69,7 @@ func TestLastKnown(t *testing.T) {
 		frame := tf.LastKnown()
 		assert.Equal(t, latest.Time, frame.Time)
 		assert.Equal(t, latest.Point, frame.Point)
-		assert.Equal(t, latest.Altitude, frame.Altitude)
+		assert.InDelta(t, latest.Altitude.Feet(), frame.Altitude.Feet(), 1)
 	})
 }