TrueNAS works perfectly as a VM eg on Proxmox with passing through a SATA controller from the motherboard. It may not work always with bad IOMMU groups, but I have this on an old Xeon Precision Tower 3420 and not so old Asus Z690 motherboard. NVMe passthrough should be straightforward as well. No need for LSIs or cheap PCI-to-SATA cards if the number of existing physical slots is enough. And as far as TrueNAS is concerned, it's baremetal disk access. Even the latest TrueNAS is not in the same league as Proxmox for managing VMs/containers, not even close.