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.
This sounds an awful lot like the PS3 OtherOS class-action lawsuit that Sony had to pay out on.