You know... This is probably an odd power possibility, but what if rather than having her hair long all the time, she could actually control the length? At first it would be kind of wonky and definitely longer for most of the time, but maybe over time she could make it more manageable if she wanted to. And then if she uses too much of her powers or something, a side effect is a day of suffering super long hair, lmao. But all with the telekinesis like element like you said! I think that would be cool and definitely more useful hah!

I was actually thinking about that earlier today! About whether Alice in Wonderland would also be an interesting fit for Weiss. If you'd like I could try and help brainstorm ideas for that if you're interested, but if you're more settled with Rapunzel then no biggie!