i dont know why or with which version this has changed or if this bug has always existed or not, but ive been trying to get cargo trains working on my local minecraft server but if i set anything faster than [msp] 2, and have a chest minecart travelling behind my minecart, the chest minecart creeps up and runs into my minecart, causing slowdown and often even making the chest minecart go backwards after i pass a curve (with the speed set to [msp] 1.2 to stop derailments)
perhaps u could add some code to set a slightly lower top speed for chest minecarts, since they dont correctly obey the max speed function