I get CPU bound a lot of times with my 5800x in VR. Usual CPU frametime is from around 10ms in single player with little going on and up to 25ms on busy servers with a lot of things going on, and up to 30ms+ if something cpu-intensive is happening close by me. My GPU frametime is usually much more stable than the CPU, and around 17-19ms. The CPU frametime kills FPS in multiplayer. People can go on and on about stuff doesn't matter for 4K, and VR is even higher, but I have tested it with fpsVR in DCS, and it it is pretty clear that heavy missions kills frames in VR because of CPU.
If the 5800x3D cache have good effect on DCS it will be an instant buy here. I own a 5800x already and it will just be to just swap it out and the system might be able to live until DDR5 gets cheaper (Zen5 maybe). I'm just waiting for some of the others here that said they have already bought it, and hope that they report back soon with their findings.