Is all SSD pool worth it on FreeNAS / TrueNAS Core

I am currently running a 12 2tb ssd array (Main pool raid-z) and a 8 4tb wd red array (Backup pool raid-z). I have been getting errors only on the Freenas screen for the SSD pool. never in the web interface. I run all my movies through PLEX and do some light video editing with this box in the main pool. I did a major backup of my actual Workstation to the hdd pool because my movies and stuff take up quite a bit of room on the ssd’s I noticed when I was transferring the files I was able to write to the drives at the maximum speed that the drives would read from my main machine over a 10gig network. Right now I’m running 11.3U4.1 and when Truecore 12 stable comes out I will probably upgrade to that. I have been watching a bunch of videos on it and trying to decide if I should get a set of bigger HHD’s for backup and use the SSD’s as cache drives for the HDD’s.

My plugins are in there own 3 2tb SSD raid-z pool which also houses my VM’s

My thought is use 2 or 3 of those SSD’s as cache drives for the HHD’s use the others for a video editing Pool only.

I rarely but do edit 4k video.

Would I see a performance hit to Plex which is shared to a bunch of friends outside my house?

What are your thoughts?