[o11c]

I accidentally enabled debug mode and figured out what's going on.

Whenever you click on the L0, he always teleports to an unoccupied square. Only if there is nowhere left to teleport do you get the 10XP. Since the scroll of orb uses similar mechanics to find an unoccupied square, that means it is worth using relatively early.

Incidentally, with perfect knowledge, there are at least 18 spare HP (it depends on how much XP the 1HP and 2HP walls happen to give). So theoretically you can get a score of 303 without using the last heart scroll. Without cheating the best I've done is 13 HP remaining when using the last scroll.

The only time I've got a score of 302 is when I didn't use the scroll of orb. Unlike scrolls of HP that one does seem mandatory.