Thank you for the detailed feedback! It means a lot to me that you think it's so well done - I wasn't really feeling all that good about it during development, so it really lifted my spirits.
Regarding point #4, why do you think the movement would feel better if it were acceleration-based? I don't think most precision platformers do that (or if they do, the acceleration is incredibly quick). I'm reusing a character controller I wrote myself, so I could easily turn on the acceleration, but I thought it would be better without it.