^I agree. I think chain speed has alot to do with the placement of the mcbr. Newer B&Ms have significantly faster chain lifts than old, hence the train will have traversed a farther piece of track and there's a possibility to place the mcbr later without loosing capacity.
BUT, I just wanna stick in that I hate late mcbrs!! They absolutely kills the pace! Grand examples are Shambhala and iSpeed. Both have just a turnaround and a small hill before the final brake run, and both are relatively lacklustre and turn in to a mere transport distance to the brake run. I would much have prefered to just skip the final portion of these rides! Or having an earlier mcbr.
Btw, a question to those of you that is/have been working as ride operators: how often are mcbr actually used? I would say I'm fairly well travelled with ~200 coasters in several different countries, yet I've never seen the use of a mcbr. What I mean is that I've never seen two B&M trains on the actual ride track at once, not even in three train operation. At best I've seen one on the lift while another still traverse the track. It seems that ride operators have to be REALLY quick to actually have any use of the mcbr at all!