Free and Open Source Software

In the sense I think you're asking, never: contributing a fix or an improvement is never a one-and-done, fire it off and forget it edit. Each contribution is a request to open a dialog. Implicit in each pull request are multiple questions, perhaps including "is this a good idea", and "do you like this attempt to do it".

If the project maintainer who reviews your PR doesn't like it, they can expend the effort to try to explain why, and teach you. So try to make their job easier, by opening with a clear explanation of why you're doing it, and if what you did involved design decisions, why you chose as you did.