I’m not really a professional developer, so maybe the answer to my question is trivial to you guys.
Anyway, I’m only doing custom java scripts, no server side changes.
I have this mod: Google Maps with Location Distance Integration Tutorial
In order for it to work I had to customize frappe hooks.py
Now after each update I have to do git stash, bench update and git apply.
And then bench install-app frappe to get the modified hooks.py into my site.
So the question is - is my approach correct? Or is there another, simpler way to add the Google api to avoid server side mods to frappe and thus simplifying update process.