@robi I finally figured out how to get it work and play nice, with no thanks to Firewalla. Their customer service is by far the worst I've encountered and they don't provide any networking advice. Thanks to your documentation though, I learned a few things and changed the NUC to have the outbound IP address in /etc/hosts so *.62 my.nuc.com, along with additional lines for local networking. After several repeated reinstalls of our script (sorry, I commented out the lines that check if nginx, docker, or node are installed), I was able to get it work, but it was hacky at first. The issue here was that Cloudron does a request to get the IP address. Since I couldn't EXACTLY figure out how to tell Firewalla to assign that outbound IP to the machine, it would receive my default IP.... *.58. So, after it said "success go to *.58" I went there and it loaded up locally and then went into Cloudrons network config in the UI and specified .62 as the IP address. This then matched what I had in Cloudflare and was able to get everything back up and running!
I did have to make a change, and, again, thanks to your documentation it made it super simple. Email wasn't working. So, in the Firewalla I set the domain to "mrvl.lan" and then made the changes on the nuc to have:
server: private-domain: "mrvl.lan" domain-insecure: "mrvl.lan" forward-zone: name: "mrvl.lan" forward-addr: 192.168.195.2
I go back to the Firewalla and SSH into it and find their Unbound config, and added this line a line for "local-data-ptr" that has the WAN IP and the mail server domain... and... FINALLY.... it all worked. Now the only thing left is to mount my NAS to it and go crazy with apps as it's loaded up on memory (64GB) and plenty of onboard disk space LOL. I may be requesting more apps soon, specifically Plex, Radaar, etc to take the load off the NAS (it doesn't do Plex while having some VMs running).
Anyway, sorry for the long post. I'm just super excited to be out of paying Vultr $60+ a month and to have it local on a much more powerful machine, so I don't have to toggle apps on and off anymore. It's glorious!