Good questions. I actually save NO boxscores/pbps, not even for human leagues. I set the sim display to dialogue view, i.e., no details, no scrolling headlines, etc. All that I care about is to sim and accumlate history.
Actually I went back and created a US only historical league last night (so much for my resolve to shelve the game
...it's a love/hate relationahip) and simmed through 6 months in a mere minutes! Unfortunately it crashed at that point during player import.