Thank you, this is exactly what I was looking for. I guess this means if I wanted to make existing scripts compatible, I would need to do a large-scale replacement of relevant copies of ApplySpell with ApplySpellRES.
I asked the part about CLAB files because it did not initially seem to work for me, but it turns out it's because I typoed the resource name. How embarrassing.
Anyway, obviously it worked perfectly after fixing that, but unfortunately, I was then able to test opcode 172 with 8-char innate spells and it seems like it behaves exactly the same as it does for 7-character resources -- all the "memorized" copies disappeared. Perhaps the behavior noted in the IEDSP is only for wizard and priest spells? Anyway, unless I'm somehow screwing up again, it looks like I'll need to find another method