So one thing I have noticed since beta 5 is that EGPU performance in games and simulation intensive applications where I rely on my 5700xt in my Razer Core x has really gone downhill. In simple games like world of warcraft my external GPU can barely get above 40FPS at low resolution and low settings. My internal Vega 20 can do 60 no problem. The 5700XT is a much better GPU and capable of out performing the Vega any day of the week. In fact on Catalina, it does just fine. Same game 60-90 FPS, on Catalina. The results are apparent in Geekbench as well where the opencl benchmarks drop dramatically when using Big Sur.