Whats the difference between sideloading and installing? I don't get it tbh.
On windows for example, it is the norm to go online to a website, download an exe and double click it - instead of going to the microsoft store. And both are ways to install software. Neither way is doing it sideways.
But also
I can easily see fork related infrastructure for end users making it really eash or automatic to keep up with that cycle.
There could be a store that installs software from github (there already is) and additionally tells you "hey this app you have got forked and the fork has more development happening, do you want to switch to that one and migrate all your settings? y/n"