Soldato
NordVPN are shady, for various reasons. Ask for a refund and get a VPN that is more privacy conscious such as Mullvad, AzireVPN, VPN.ac or similar. You can use WireGuard, OpenVPN or IPSec on USG, but only the first will have acceleration and operate in kernel space (as per reply above). It's still only a small CPU though so don't expect much. Better to connect each device individually if possible, on an ad hoc basis.
What's Shady about Nordvpn, have only heard good things about them and been using them for a few years now?