The only reason to limit mechanical advance

Lol, that's even more impotent than a politicians answer, let alone less competent! "There's always a reason", no **** Sherlock. He is either completely clueless, or thinks He
has an explanation you won't understand. Either way, You are pretty much correct, although it doesn't always have to be related to transfer port/slot exposure it can be. The
basics are to get the perfect timing for the engine at idle whatever the cam/t-port sync/intake(w or w/o heat)/exhaust etc. for best idle & response, then yes, if the total is
beyond where you need it for max HP, it has to be limited. Rarely does the OE mech. advance need extended, almost never.