The official Microsoft .NET Core debugger, vsdbg, is still proprietary and only allowed to run on official versions of Visual Studio and Visual Studio Code. (VSCodium/vscodium#82)
To provide a complete development experience on MIPS, we need an alternative to that.
Maybe https://github.com/Samsung/netcoredbg from Samsung? It contains quite a bit of C++ code that requires porting to MIPS.