Trust me, I also got hit by that same confusion in my first playthrough. 😆
If the fences were introduced early on in the levels, then players would’ve known that the fences are platforms. That is, if the Ruby Forest stage was extended.
The third boss was pretty easy if anyone played the prototype, but as you mentioned with the hitboxes, it’s hard to guess how high you’ll jump in order to go through them. This problem is the same to Bayla, but never Rubianne.