Should the present BASSA leadership stay in situ as full time officials the IR relationship with BA would be in danger of remaining in a state of permanent dispute. I cannot see BA allowing that to happen and will find (legal) means to sideline the likes of DH and LM unless Unite reel them in.
As an aside, I was meeting friends in Covent Garden last night and was gobsmacked to see a rather fine building right in the middle of that area belonging (or rented) to Unite. Why is it neccessary for a union to have offices in one of the most expensive parts of London?