I added a list of box counts and secret spells used for my scores in my comment below, if that helps (although if you want to actually solve the puzzle yourself you shouldn't look at it). The problem is that the best scores aren't actually known (although I've seen a bunch of score posts and haven't seen any higher than the scores I posted).
Boxless, limited boxes, and no secret spells are also all reasonable things to optimize, but as far as I know no one's actually bothered except for boxless (I've seen some pretty good boxless scores, but likely still quite far from optimal).