I haven't tried this yet (having network "clients" that just hook in yet), but im thinking the way to do it would be:
1. Create the network you want to create, "Network A".
2. Create a network with single "gateway" node, ("Network A Gateway"). The single node must also be in "Network A" and is probably your netmaker server.
3. You can set up wireguard manually on the mac, connecting it to the gateway node using the endpoint and public key