Thank you for such in-depth analysis, Walter!
At the moment, Welkin's portrait and a function to disable NSFW are the only two features I could easily implement (but at the cost of story development). At some point, I will ask the patrons about these and let them vote to decide.
As for the other functions like "skip seen" or UI buttons - the engine I use to create the game doesn't support such things by default, and even the community plugins doesn't always works like intended. Sadly, the bigger this project gets, the more I start to regret for not sticking with Ren'Py like everyone else. But becasuse it's too late now to move the project on the new engine, I have to continue with what I have.
And yes, I will probably add Welkin's character profile info at some point too (I will have to draw his sprite first, though).