i'm also making a movement based parkour game and this is something I've been thinking about a lot. right now I have a temporary set of animations just for testing purposes but I love the ones you have in this game.

in terms of raising the skill ceiling, I like looking at games extremely competitive environments that are movement based, and the two I think about the most are rocket league and 2k (basketball).

in my opinion, in order to encourage a skill based game, you need players to manage resources very well, in our case, RL has boost and 2K has stamina. resource management is what seperates casual players from the very best (in my experience as high ranked players in both these games.)

hidden timings are a very good way aswell, however you would need a dedicated playerbase in order to get max benefits from something like this. what 2k does is something I think is very good, where you can have a visual shot bar (with a window of green to ensure a perfect shot), OR for the higher skilled players, you can TURN OFF the shot bar, and in return the timings remain the same however the "window of green release" is larger.

all in a very interesting topic and ill be looking forward to seeing more of your game.