I'm curious why did your progress with Rust stalled and at which point? I’m starting to learn it and so far I haven’t noticed any productivity blockers.
Also, the organization has no desire to invest in training or experimenting. The project is funded by the "business" and they want to see a business result in return for their money ... so you basically you sneak in a bit of time as you try/test something new. Nim won out by somehow getting a team with python expertise learn and deploy their product fast enough.