issue15110 introduced a new private function, _exec_module(), to the default loaders in Lib/importlib/_bootstrap.py.  Doing so helped hide importlib frames from the traceback.  A related fix is likely required for issue15425.

Should some general form of exec_module() be an official part of the loader API (in importlib.abc.Loader).  If a loader subclasses one of the default ones, it already gets the behavior for free.  Otherwise it does not benefit from the cleaner traceback (unless the author is savvy to the _exec_module() implementation detail).

Though the use of Loader._exec_module() to strip tracebacks is an implementation detail of CPython, having a public Loader.exec_module() would allow other implementations to perform a similar action.  And if we found a way to move remove_importlib_frames to importlib then all the better.  (Looking into traceback API improvements is on my to-do list.)

As a bonus, Loader.exec_module() would also allow loaders that wrap other loaders (yes, esoteric) to manage the execution portion of loading.  I haven't given this part a lot of thought, so it may not be much of a bonus (or could even be a negative).

From the perspective of caution, the import machinery is already pretty complicated.  It may not be advisable to add to that even in this little way.

This isn't going to be worth it.