I think you need to have separate servers. One for Proxmox and one for TrueNAS.
Your motherboard gives you 3 M.2 slots and 4 SATA. That would be usable for Proxmox.
The HBA and it’s attached drives would all be only for TrueNAS since you have to pass through the entire controller and blacklist from Proxmox.
You are also out of usable PCIe slots with the HBA and NIC occupying two out of three available. You need to match the card requirements to the slots. If you wanted more drives attached to the Proxmox, you need another HBA.
I think you need to plan one server for Proxmox and one server just for TrueNAS.
I was guessing TrueNAS was going to store the videos, photos, and various personal things.
Try reading through the following on ZFS primer, pool layout whitepaper and the special devices (sVDEV). SLOG is for ‘sync’ writes and has special device requirements or suggestions.
BASICS
iX Systems pool layout whitepaper
Special VDEV (sVDEV) Planning, Sizing, and Considerations
SLOG is not a write cache. You only need it for sync writes. So databases, Block storage (iSCSI, zvols for VMs), and NFS.