I am talking about the thread that honeybadger linked and authored.
Arwen’s argument maps with this paragraph in the blog post, but it is vague on details.
Hypervisor-backed virtual disks or hardware RAID controllers provide a “translation layer” to the disks, and therefore should be avoided for the data disks. TrueNAS boot devices are an exception, and can be stored on a hypervisor virtual disk safely – but it is suggested to create two identical volumes and use the TrueNAS installer to mirror these within the guest OS as well. Ensure that the underlying physical storage backing these hypervisor virtual disks is sufficiently redundant as well.