I personally really like StartAllBack. I just want a clean classic Windows experience.

Honestly, I feel like they’ve made side loading easier and easier as times go on. Used to be that you’d just get a pop up that installs weren’t authorized for that app, then you had to dig through the settings to enable it. Nowadays the pop up has a shortcut to the correct settings page and even visually flashes the right toggle for you to make it easier to find.