I haven't encountered the terrain collisions which you describe with Rose but that's probably because I don't try to carry a charged shot for a very long distance- I am however very familiar with it due to the heavy interference the terrain inflicts on the Unicorn Chompers Rainbow Warp ability.
I gotta agree with OP here. I don't use Rose much, but not being able to jump for charged shots is a huge hindrance. Sometimes the target is behind a fence or wall that you could normally hit if you could jump, forcing you to give up ground to get in position for a clear shot.
I think they should be able to jump, but then you have to cut some damage, or make the charged attack, charge itself slower to balance that, i think they're both fine, but nevermind for a good healthier change
