Not a normative question.

I've tried adding reflect damage spells to NPCs, but they refuse to cast them in combat, even if it's the only spell they have. I suspect that, based on the magic effect code, NPCs might actually consider reflect damage a spell to restore the ReflectDamage actor value. Nothing I do causes the NPCs to start using the spells, but I would appreciate it if anyone could confirm my theory about the magic effect.

They won't use Spell Absorption spells or potions, either.

I've encountered NPC's that definitely have these effects. I think they have them as abilities and not spells though. NPC's don't have much magicka and they won't use spells if the cost is too high. Have you tried making the spells abilities? I think you'll find they use them then.

That's not what I'm trying to achieve. I'm trying to have NPCs supplement their spell selection with Reflect Damage spells. The costs aren't too high, it's simply that they won't use the effects (they won't use spell absorption or reflect damage potions either, but will use reflect spell potions, so there's something wrong with the effects).

NPCs are supposed to use spell absorption spells in vanilla, but if they won't cast them, then two out of four Mysticism effects assigned via leveled spell lists (dispel on target and spell absorption) simply won't be used, which is clearly not intended behavior. I need to know if it's even possible to fix.