Wouldn't that be nice. The image stays the same after 175. I just enjoy playing the game, though, so I don't mind it. I do think the B-sides are much too long for how perfect you're expected to be with that kind of difficulty. (The harder something is, the shorter it should be, imo, which is why I really love the C-side levels and didn't mind getting the Golden Strawberries there)
They should give you SOME kind of reward to absolute completion!
I agree with you: the B-sides are too much! I feel like I'm in a Super Mario Maker tournament every time I even attempt. It's fun to try though! Sometimes.