I believe this is acceptable to include in 3.8, provided it makes sense for 3.9, so I added the backport tag on the PR.

That said, I'm not making any comment on whether it's appropriate at all :)

For Windows we found some ways to reduce the stack usage of debug builds (IIRC, refactoring some large local variables into their own function) and improved recursion depth that way. Without any data on whether worker threads generally go deeper than the main thread, I would hesitate to say that they ought to be the same, as there is a definite advantage to having a smaller stack by default when you have many worker threads.

But if someone else confidently approves the change, it can go into 3.8.