When exactly are you defining as “traditional”? The Python point releases have generally been painless for a long time. There was a little friction in the early 2-3 era before they made it easier to write code which worked on both without translation but in general it’s been at least a decade since I’ve cared about this except for one time where a couple of libraries depended on a private API which changed in Python 2.7.9, and that was back in 2014.

https://bugs.python.org/issue22438