Simple way for sort-off running Airgap vault on desktop computer is by using some kind of Android emulator, best I know are open source Waydroid, Anbox or Genymotion Desktop.
Nice stuff. I've been trying to look for an Android emulator that actually works (and is free).
Blocking peripherals is a hard task, especially if you want your keyboard, mouse and biometrics to remain and some devices could disguise themselves as that - you might be better off using an open source VM for this, controlling the clip pard and limiting Internet access - it's much easier to guarantee if it's segregated. I've seen an example of one of these online but haven't looked into it too much in the past - you can obviously use VMware or virtualbox for the same thing (they're free but not open source).
So I'm guessing that the only way you'd be able to send biometrics to such an airgapped wallet is to collect them from the host system and then pass them through to the guest VM via a virtual serial port.