Is there any advantage in running FAH on both a virtual machine and the host? Are there many members here doing this? Anything I should be aware of? TIA and I appreciate you folks' work of love here, very muchly.

Short answer no.
You're better off running fah natively.
Virtual machines have overhead, and are slower.
You could run everything in a virtual environment, in case you want to keep your local data safe(r).
But doing both defeats the purpose of a virtual environment. You might as well run it without a virtual machine.