How to reload a module that was loaded by another module?

Question

I have an intermediate module that serves as an export_file, however, at development time, I couldn't figure out how to reload everything that the export_file has imported.

main_module.py

def func1(): print("func1")
# def func2(): print("func2)  # to be uncommented later for testing if reload worked.

export_file.py

from main_module import *  # for sake of simplicity.

Finally, main_file.py

from export_file import as exp  # for simplicity

Now, if func2 is uncommented, how can I feel the impact on main_file.py? I tried reload, importlib, runpy modules, run them everywhere, added a special function inside export_file for this purpose, but I couldn't get it to work, neither for love nor for money.

EDIT:

exact sequence of commands ran in main_file interactive console