It's going to be the same as Play Protect using the PackageVerifier API. Even if won't trust that Play Protect will continue to allow adb installs, if you go to the developer options you can disable package verifiers for adb installs.
>the concept
This would not really work considering you can't do a lot of things at runtime. You can't create activities, you can't create services, you can't declare permissions, you can't use permissions, etc. Pretty much everything in your manifest can't be done properly. You can't really do a job faking it. You would have to declare a ton of dummy activities with all different permutations of things like launch mode, document launch mode, intent filters, etc.
What you can do are things like game engines like how the android godot editor works where you aren't loading full android apps, but projects into the editor.