When it was all 88’s from my commute airport they routinely broke. At least 4 times in 2 years my primary went TU. I made the call and got PSC on the backup. A couple times in was full and somebody got bumped. Never got a call.
I’ve mentioned this before. I would GLADLY trade my travel “benefits” for PSC if given the option. I’m about the be a 3 digit pilot here, so it seems that trade would benefit others.
Also there seems to be an unwritten LOA that when the GS are flowing you can get a PSC commute to work. I’ve even spoken to scheduling and said “gee, I’d love to but……” Miraculously I got a seat. Supply and demand I guess.