It really wouldn't be that hard.
We already know they're planning on adding (A considerable amount of) new skills to BLU come the next update for the job.
They just need to make some of those skills comparable to the current "Must haves" and then put them in the Overworld or as Totems. Then it's done, literally the entire design I outlined for making BLU both not restricted while retaining the essence of BLU (If we assume that the current implementation is capturing the essence of BLU) is successfully created.
Just add more skills, make some easier to get. Just like they have now. The only thing you need to do is make it so that the easy to obtain skills aren't just garbage like Final Sting and at least have some that are like actually relevant skills such as The Ram's Voice.
Then it's just balance changes to the trio of problematic skills, which hardly needs an overhaul to the entire BLU.