That's exactly what I want as well, phones are powerful enough to do that. I could even use the phone screen as a second screen terminal and type with my keyboard in both, switching with ctrl+something.

Everything is technically complicated on Android, I've also worked into customizing ROMs, trust me, Android kernel & top layer are so clunky that it's even a miracle that the phone is switching on. There's really nothing we can save from this garbage system. Sorry for the Android fans reading this but that's truly my personal opinion after digging into it for a few months. it's just piles and piles of hacks as far as the eye can see.