Well, on the one hand the Westsiders use only mini-bands with bench, whereas they’ll mix and max light avg and strong bands for squat. So my bet is that they dont circa-max their bench because they cant mess around with the band tension on bench with the same ease with which they can on their squats.
HOWEVER - the whole firggin point of Westside is experimentation and people finding out what works for them. So why don’t you give it a try? DOn’t ask me how to set it up though, I’ve only been lifting westside a few months and I feel I am not yet advanced enough to start circa-maxing. Hell, I squat 445 at 198 so i feel I’m not even advanced enough to squat with bands. Just chains for now.