Im currently building a ui framework for unreal. I dont enjoy ui work so I wanted a way to have to write less ui.

For me I dont look too closely at the implementation but I look at the api where if a human was using my framework how is the code they'd have to write and engage look at. Then I also do plenty of performance against a comparable target in my case slate (default unreal) and keep overhead minimal.

So good performance and reasonable public facing api are the 2 main pieces im focused on. Less with the internals.

Care about the seams and interaction and the things you can measure or count.