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

I use it. It’s just as easy to set up and run as the other two, whether you use the tarball install, repo packages, or docker. While you’re at it, look into Prowlarr also to manage your indexers and download clients so you don’t have to make changes on all 3 manually. Then maybe look into Ombi to manage download requests. I like Overseer better, but it doesn’t support music yet, unless something changed recently. The biggest hurdle is that in contrast to the TV and Movie categories, the file naming conventions for music downloads are not nearly as well standardized and enforced. Lidarr does a great job of shifting through and finding what it can, but I still get a lot more releases that require manual importing than with Sonarr or Radarr. Maybe I just need to tune the filters better. Discovery isn’t really something Lidarr does yet, although there may be some forks working on adding it. Last.fm or listbtainz can help with that, or there are a bunch of self hosted media trackers that have recommendations built in.

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.