Until then just buy 3-4 additional graphics cards and place them unopened on top of your tower
May I also suggest overclocking the GPU and CPU using duct tape & watch? The more the better. You still have to be mindful of good airflow though. Putting the PC into your fridge might be the sweet spot.
On a more serious note. My Radeon RX 5500 XT (8 GB) runs PHG on solid 55ish FPS (I think, will check that out) on high settings FullHD with V-sync 60 FPS frame-lock enabled (old display; my GPU is for 1080p gaming anyway). I do experience occasional frame drops etc. I agree that the optimisation needs some more love from the devs.