My understanding is that hba cards support virtualization better than passing sata directly through. But if you’re not virtualizing the NAS, I wouldn’t see an issue with a reputable motherboard that has enough sata ports at 6 Gbps.

For the cheaper expansion cards I’d see that as a central point of failure and would recommend an hba card over a cheaper alternative.

Define “due taxes”? It’s all a net loss bc “we” paid so much in nontaxable stock options to our senior leadership so they could borrow more money and buy a 2nd plane to get from their private island to their new boat.

For #3 officially, nesting TrueNAS in another hypervisor and then using it as a hypervisor is not really recommended, especially with any kind of virtual drives. It could lead to challenges. Virtualizing drives is definitely not recommended and the most stable choice is passing pcie through with a hba card.

Given that, I have a similar setup and I’ve made backups for important data, I passed a pcie data/SAS hba card that I connect any TrueNAS drives to directly instead of a virtualized drive.

https://www.truenas.com/blog/yes-you-can-virtualize-freenas/