I wouldn't trust entirely airgapped devices.
Even airgapped machines might be infected via BIOS/EIFE (and or hardware drivers) malicious payloads.
Once you formatted the computer and reinstall the OS, there is no problem.
Nope, there still are problems as
BIOS/UEFI viruses can survive formatting and/or reinstalling.
The same is true for malware hidden in firmware of HDD/SSD.
Thus my stance on the preference of HW generated SEED stands unaffected.