There was a case in which Back and Front were both needed as well (Not sure, but I think it was somewhere in the installer?). 

Mostly, I've done it this way so https://github.com/forkcms/forkcms/blob/release-3.5/app/routing.php#L98-130 remains clean. With a few extra lines there, you could specify Backend or Frontend depending on what app gets loaded. Regardless, it's not a big problem to load both imo.

@dieterve Just like my method description states, it's indeed a temporary solution to keep everything running until we move away from the "static models".

Removing the require statements is something I'll have to try tomorrow (can't test right now). I think you're right though, the autoloader **should** pick them up.