I would say use your NVME drive for your VMs, particularly your gaming VM. You dont really need NVME as a cache drive unless you are looking to transfer files to your system quickly but unless you are using a 10GB NIC you will not get any benefit with an NVME cache drive as a SATA SSD can easily handle gigabit transfers. If you are using plex dont forget to transcode to ram, you have plenty in that system.