Any modern PC is a goddang supercomputer, and there's no excuse for yet-another-RPG running poorly.

Do less per frame. Do things less often. Or just uncouple your main do-stuff thread from the show-stuff thread, so the game renders at 60 Hz, even if everything but your character updates mere dozens of times per second. It's not a twitch shooter. Giving dudes an animation to play and a vector to run along is perfectly fine for interpolation between what's-this-guy-doing events.

You can favor anything the player's looking at. You can favor anything gameplay-critical. Cheating your ass off does not have to mean enemies run against walls or run through walls. But it shouldn't mean an engine you've been using, for years, runs like you heard about optimization on the back of a cereal box. You had time to bodge this sort of nonsense.

"Will it run Crysis?" was a cute joke back when devs had no idea what they were doing... and still gave artists every new effect they could describe. All those gimmicks have since been distilled onto a potato, and then surpassed by physically-based rendering, which also runs on the potato. This game looks like any current PBR pipeline... but slower. Honest warnings would be better, but if you did it right, there'd be nothing to warn about.