Every psychedelic I've taken has had an upper-bound beyond which increasing dose didn't really do much. Granted I've never taken astronomical doses of LSD but a "heroic dose" of psilocybin will take you places a "heroic dose" of LSD can't.
I'm sure it's possible, but I haven't heard of anyone eating a sheet of acid who wasn't at least a little messed up afterwards.
In case you missed this article about monster doses of LSD, you might be interested: