Personally, I might be prepared to accept a scope clause if the following conditions were met :-
1. Inclusion on mainline seniority list based on DOJ of original company (Brymon BRAL etc.).
2. Inclusion on mainline list open to all BACX pilots irrespective of aircraft type and rank. (i.e. not just jet/146 captains).
3. No interview or flight test to access suitability. If you're good enough to fly for BACX, you're good enough to fly for mainline.
If on the other hand, mainline CC want to impose a scope clause while at the same time selectively restricting access to their seniority list and ensuring that our most senior captain becomes junior to a direct entry cadet who joined yesterday, then they can stick their scope clause where the sun doesn't shine, which would at least have the beneficial effect of muffling those of our mainline colleagues who use this orifice to speak out of!
We are the BRAL collective ~ Resistance was futile, I have been assimilated!