I do for some private repos. It's really handy to be able to clone a project onto another device and have all the configuration included. Run/test configurations for example. Otherwise maybe I could see it being useful for teams that all use the same IDE?

I'm not familiar with the check routine, but going off of a quick Google search, it seems that it performs some linter functionality. I use ruff in Python. docs.astral.sh/ruff/

Nice! This is a fantastic use case imo.

Whenever I reach for a typed dict (or a named tuple) I have to ask, why not just a full on class/dataclass? And a custom class is almost always more appropriate. It also has the benefit of lowering the surface area of my code, a dict brings along a lot of unnecessary behaviour with it.