Not keen on your data store choice. Mongodb introduces a lot of other problems. The problem with schemas is an easier one to solve imo
For the problems you're mentioning, what we've seen is that many people use it incorrectly, and we're building the framework in a way that prevents that in the app layer. But still curious about your experience - what are the biggest problems you've had in production MongoDB?
I would never go full mongo considering how easy is now a days to have TypeScript first postgres.