So things have changed recently, Ingress is up allot, I’m seeing TB’s of ingress, where before there was a few 100 GB’s - It’s a good time to optimize your setup.
I posted this yesterday, covers the basics of ZFS on proxmox and the memory requirements - good you have 2 disks, so reads will be ok 
you might benefit from a L2Arc on SSD on NVME being added - check the memory being allocated to ZFS hopefully you have 32GB plus in the server, afraid that’s where my ZFS expertise ends, I know SNO’s did some comparisons but can’t find it in search on if it helps much using L2Arc…