With my experiences playing the game with an unsupported GPU and getting a solid 60 fps still as long as no NPCs are in the vicinity, I don't think it's the GPU side of things that needs optimization. It's whatever uses the CPU.
It could be optimized better for intel. They have had that issue in the past.
Though... I limit my voltage to keep it from shooting up to 95c from their latest firmware updates (AMD cpus push themselves to the thermal limit intentionally), I kinda wonder if that is having an effect. It's never been a problem before, however.