Unite have full time negotiators and more experience. I have no issue with Unite handling initial negotiations provided that the negotiator is correctly and fully briefed of cabin crew expectations, and does not commit to any decisions without refering back to bassa in the first instance.
It would start to rebuild bridges if bassa were allowed back into negotiations after the initial stages.
I have faith in the cause, but I do not have faith in bassa leadership. Perhaps bassa should nominate new negotiators.