I also have extensive experience with mypy and pyright, also even going as far as trying to fix a mypy bug (also unsuccessfully). For pyright, the dev was so re

I also have extensive experience with mypy and pyright, also even going as far as trying to fix a mypy bug (also unsuccessfully). For pyright, the dev was so responsive that I only had to report bugs for them to be fixed (sometimes in a couple of hours). It's been a year or two since I've touched Python, but back then, Pyright, was way faster, was more feature-complete, had a much more responsive dev team (of 1). It was better literally along every metric: except that it didn't support custom extensions to the type system like mypy did. But that wasn't a huge issue since there were very few extensions, and even the one that was developed by a mypy core dev for sql-alchemy was hopelessly out-of-date, or impossible to get working. So I didn't miss it much. All this to say: pyright was much better.