The HBB is legal for SASS... though it does not lend itself to either speed or 19th Century Design... never the less SASS approves it.
By and large, the most CAS matches you may run across are SASS matches.
On the other hand, NCOWS has not approved the Henry Big Boy, nor Winchester ’94 with angle eject or any Modern lever-action rifles in current production equipped with angle eject, ramped front sights , H&R Buffalo Classic and Beretta Renegade.
(The Beretta Renegade is excluded because of the Factory Short Stroke) which is not allowed in any lever-action rifles/shotguns or
Aluminum carriers for toggle link rifles.
I doubt either of the Clubs you're looking at ( being SASS ) will "ostracized for not being
" Politically Correct " for my choosing to buy the Henry"...
rather, I suspect they will be friendly and glad to meet you.
Even NCOWS Posse's are accommodating, and would not send you packing...They would request & require to you to acquire an approved lever gun within one year, should you continue to shoot NCOWS matches