Dear xize11,
I don’t think that’s exactly the case. At the office I have a modem that connects to the internet. The wan port of the SF1200 connects to the lan port of the modem and I use the PPoE passthrough feature of the modem and connect the SF1200 with PPoE to the internet. The modem and the SF1200 have different (both public) IPs assigned. If I understand it correctly this means that there is only one NAT (of the SF1200) in play. When I check the netwok settings of the modem (which has a ip range of 192.168.0.0/255.255.255.0) the SF1200 does not have an ip or appears on the port forwarding list section of the modem.
The client 192.168.1.10 is at home behind a modem (192.168.1.1.) that has a public ip address and wg ports forwarded.
I hope this makes the setup more clear.
Unfortunately the internet provider does not allow different modes and the modem does not support wg and found the vlan setup quite complicated, thats why I decided to buy the SF1200 and use the PPPoE