Unfortunately, with the new RC my FPS dropped down from stable 90 to lower than 50 in WMR even with one car without rain. This makes RF2 practically unplayable. I tried several combination of the official content. I also tried cleaning shaders and cbash folders, checked integrity of files. Nothing helped. I used to play with almost everything on "off" in video settings, so left the video setting unchanged. As soon as I returned to stable built I got stable 90 FPS as usual.
My specs: AMD Rysen 5 5600X @4.8GHz, Asus GTX 1080Ti @ 1796 MHz, 16GB RAM, SSD, WMR helmet - Lenovo Explorer, Windows 10 with all the latest updates.
EDIT: Deleting player.json solved FPS problem. If I find time I'll try to investigate it further.
EDIT2: This was the only line of Player.json causing the FPS drastic drop: ""Max Framerate":92,". Returning the value to "0" solved it. In previous builds it helped not to overload too much GPU.