I'm leaning towards a hard NO here, but it's hard to test this sort of thing because I am uncertain if loot is determined on spawn of creatures, or on death/loot.

If loot is determined when something spawns though it's confusing how loot luck even works at all.

I know this is a very late response, but I just joined the Obsidian community. I'm somewhat of a newbie to Pillars of Eternity, and I'm not sure what you mean by cones/crinkles/waffles, but I think you're trying to figure out what determines which loot drops from enemies. I don't know if there's a difference between the PC version and the Switch version (the version I'm playing), but I'm pretty sure that loot is determined on the death of enemies. I've noticed that loot drops change depending on the exact spot that you kill an enemy. For instance, in Od Nua, I've encountered Swamp Slimes that may only drop an ooze plasma in one spot, but in other spots the same Swamp Slime drops 2 Topaz, 2 Diamonds or 2 Ta Ondra Tara. And the spots of the kills don't even have to be that far apart to get a different result. As far as to how loot luck works on a technical level though, I have no idea. I hope this helps.