For the UI/Save, once you get used to Visual Novel and specifically those made with Ren’py, it gets very easily to navigate. Right-click to open Save menu, you can also use Quick Save/Load (Q. Save/Load). And for quick decision rewind, you can even mouse scroll up.
Ren’py also includes auto-save on decision branches. Open Menu > Load > A (also Q for Quick saves). I didn’t even know about this before searching, I used to manually save on every branch, but this is much more convenient!