I have merged over issue #23810 because they are aiming to solve the same problem and the conversation is split too much.

Just thinking out loud, this situation is compounded by the fact that importlib itself has some warnings and so automatically stripping out stack frames might make those warnings look odd.

Still not sure if Larry considers this a release blocker for 3.5.0. And any solution will need to be solved in warnings.py and _warnings.c.

Some days I really hate our warnings system.