Input needed regarding storage setup

Hi

Im hoping im posting in correct subforum. Looking for some input regarding storage setup for my unraid:

As im awating deals on hardware im using a Dell OptiPlex 7080 Micro (16gb ram/i5-10500T) while wating. So i will be using my present as Qnap NAS as storage until i got new hardware and move that data to Unraid then and retire the QNAP(reuse as backup).

So Unraid will be used for Docker applications and 1 Home Assisntant VM as im moving from a windows server and Raspberry PI to Docker/VM aswell. And when i gotten new hardware with more sata ports and hdd slots i will move to that and then start using it as NAS aswell.

Until i gotten my new hardware i have (from work so no costs involved), im not wanting to buy new drives until i built the full hardware.
3 x 256gb SSD
1 x 500gb SSD
2 x 256gbs NVME

2 x M.2 NVME slots on Optiplex
1 x SATA 2.5 slot on Optiplex

Im not wanting to buy new drives until i built the full hardware.

Opt 1 (present setup as test) 
1 x SSD 500GB as array

Used size as full test with everthing configured at 3.5 gb.
-isos
-download, temporary then rrs-apps dumps it to remote Qnap media share (no cache setting to stop downloads affect io for dockers/vm)

2 x NVME 256GB as cache RAID1

Used size as full test with all dockers installed at 22.6 gb.
-appdata prefer cache setting so these folder get full speed and has raid1 for security, 
-domain prefer cache setting so these folder get full speed and has raid1 for security
-system prefer cache setting so these folder get full speed and has raid1 for security.

Or

Opt 2
1 x SSD 500GB as parity (reuse for real build as cache when its time)
2 x NVME 256GB as part of array (reuse for real build as cache when its time)
I realize that trim not supported or experimental at best.

Whats the best way until i got fullsetup, is other options i should consider?