I want to set up an SSD-only array. I'm a little confused about information out there on the internet regarding this and using unraid. Are there still issues in doing this (not with the ZFS plugin) in this day and age?

Thanks

SSDs in the parity array can't be trimmed.  They can't be written faster than parity, not an issue if parity is also SSD.

Or...

You can put all SSDs in btrfs pools, multiple pools of multiple disks are allowed and pools are part of user shares just like the array. 

 

There must be at least one array disk to start things up, but you don't have to use it for anything, a small flash drive would be fine for that.