Need help setting up new drives in fresh server build

Hi All,

I had an old Unraid server that I've replaced with a new build. I put all 6 of my old WD reds into the new server, along with 2 new reds and 2 nvme drives. I put in the old USB and was able to boot and see all my old disks and things are working fine there. I know that I don't need to preclear the new drives before adding them to the array, but will do that for the stress testing, but I have some questions for the nvme drives:

1) I want to move Plex to run on the nvme drive(s) instead of the array. I know there is stuff out there for how to do that, specifically getting the app data folder moved to cache, but I'm not sure if I want cache?

2) My ultimate goal is to have Plex and Handbrake dockers running on the nvme drives. I want to be able to connect to folders on there from my Mac and drop files in and have Handbrake automatically start converting those files and then move them to appropriate folders after. I'm not looking for help specifically on setting that up yet, unless someone has links to share now, but am looking for advice on whether I should be setting the nvme drives up as cache drives, or if I should be using Unassigned Devices plugin instead. If it is UD, how should I format the drives so I can access them from macOS?

3) Just so I can confirm the process for adding the new red drives, which are larger than all the old drives, I believe this is the process:

- preclear the drives (doing it as a stress test, I know it's not specifically needed these days)

- stop the array

- add both new drives, with one as the new parity and one as a new data drive

- move the old parity out of the array

- start the array and let it rebuild parity

- once done, stop the array and add the old parity drive back into the array as a data drive

I think I could skip moving the old parity drive out and just do it in one step, but this would give me a bit of protection in case one of the drives died while building the new parity?