A C# programmer my self, I've only just recently dabbled with renpy programming. So far programming in renpy is way faster than anything I've done before, since its super high level stuff (as oppose to low level code, such as creating game mechanics). So I'm a little mystified by this post of yours. I will say programming in renpy is the most painful and frustrating programming I've ever done... when I'm actually doing programming, but doing general scripting is fine.
looking at your mock up, my only guess as to your concern with programming is if you are trying to get deep into tailoring the look and feel of the user experience by customizing the screens, animations, etc. I will say, I'm not a fan of having to 'hard code' in the behavior I want the game to have, as opposed to a custom game where if I wanted to animate the characters in a scene, rather than using transforms and commands, I would just animate it in blender as an FBX and run it in godot/unity. But setting that up can take a lot of prep work, one of the reason I started using renpy recently is I'm tired of 'designing' games and actually want to focus on making game/content, hence renpy's script focus design encourages content creation, I'll worry about customizing the UI another time.