This

I think this is exactly what Pangolin was designed for and does.

Not knowing what your goal is, I’ll start with this: I had very similar hardware to you, and while I was fine with the Omaha Ui, I just never could get it setup how I needed or wanted. I had the er605v2, 3 eap615 wall WiFi 6 apps, and a switch for PoE from the Omaha line but don’t recall the model. I just finally gave up on it, and moved the er605 and wall WiFi APs to OpenWRT. Setup my network with a dumb PoE switch and 4 VLANs and haven’t looked back. It all just works and I almost never mess with it. I’m not saying it wasn’t a little work initially, but it’s been worth it. I’ve now added a 4th wall WIFI (just download a backup of an existing one, install openWRT and restore to the new one. Change the IP and done.) I added two managed PoE Switches with OpenWRT as well. So it’s allowing me to grow as I need to.

How long did you wait to visit the site after adding it to pangolin? I ask, because if you set it up and go within 30 seconds of saving you may see the cert warning initially. It can LetsEncrypt time to verify a site and issue a cert. it’s usually pretty fast, but I’ve seen it take up to 30 seconds or a little longer.

I’ve hit the same thing where I setup a site through Pangolin and go to it too fast, but if I just close the tab and wait about 20 seconds then go again, it all comes up with a proper cert. hope that helps.

Cheap VPS with Pangolin for Wireguard and reverse proving through the tunnel.

This!

If you can get It’s blessing I’d suggest something like KASM workspaces or WebTops, basically a Linux desktop in the browser.

This!

I use an ecobee termostat with Wifi and three extra sensores places around my home. Home Assistant already has an add-on for it, add the thermostat card and it goes to work. Set whatever automations you want.

You might reach out to the open source initiative if your app is open source. They have lawyers, and may be willing to provide guidance at the very least. I’m just guessing, and don’t work for the OSI, nor know for sure whether they will or wont help in any way. Just another place to look. At the very least they may be able to suggest attorneys who might be willing to help out.