I absolutely appreciate this post. Was thinking about doing the same CPU upgrade from an i7-6700, but seems like there is no point. The rest of mye setup includes an RTX2080TI, 16GB RAM and an M2SSD.
Have you tested the F-18 1989 CAS mission? On the carrier I get like 20FPS while the CPU and GPU are just running at ~60%. Seems like shadows, (multiple) cloud and particles (snow/rain) absolutely kill VR performance and underutilized the hardware.
Hardware monitor screen grabs: