If the opnsense interface on the WAN VLAN has a public routable IP address there shouldn’t be a problem with double NAT. Double NAT should only be a problem if they have a crappy ISP that’s using CGNAT.

Edit: never mind, I reread your comment. We’re saying the same thing essentially.

He’s trying to run it on an esp32, didn’t you read the title? /s

Image server mangled by autocorrect? Best I can come up with.

Now I’m just waiting for Netgate to announce an end to CE so I have a reason to move to OPNsense. I’m lazy and it works so I haven’t taken the time to move yet. Weird for a company to EEE their own product.