I notice those little exploding spiders in Dragonborn have a PlaceAtMe(SpiderCrumbleExplosion, 1) effect on them that handles spawning the crumbling pile of spider bones when they die.

I am wondering, if I were to use a similar method to spawn some random explosion effect as part of a spell, would it contribute to save bloat over time, or does the engine have some internal way of .Delete()ing those when they've gone off?

Explosions, and various other types of reference, are garbage collected once the game is done with them. I don't have an exhaustive list of reference types that are garbage collected in this way but explosions are definitely safe.

Cipscis

Thanks.