Also, it's becoming clear that he is coming to a personal limit of how much he can improve the emulator
I registered just to comment this.
I personally i m not excited about CEMU as a project. Is not an emulator in the way i see it, is more a Wii U game player. Also the lack of open source makes it a different project than other one out there. Those are not negative things, just my personal view over it.
I own a WII U and most of the good games that come out for it.
Now the statement is completely pointless. There is great understanding of programming and computer tech behind this emulator. Matching a 3d renderer to a different console/architecture, with all the drivers issue and graphic backend that are created and developed for executing code in theyr own way and not emulate another hardware.
This is not easy job at all. And no job that can be speed up with more people over it.
Every improvement is a reverse engineering of what nintendo did in theyr game, nothing is public at all.
There are limits, that do not come from the coder itself but from the achievement he is pursuing, having a full hardware renderer for the emulator, if you want 100% hi-fi emulation you often have to go with a sofware renderer, with all the problems we know for performances, because the 2 API will probably not match at some point.