Well, that is done! I am assuming it works. I really have no idea if it works or doesn't work! But, I've cleared out all mitractl and ufw rules and now manage incoming and outgoing server connections via /etc/hosts and /etc/hosts.deny files.
I've learned a lot about both mitractl and my firewall and Linux networking along the way on this quest to protect this instance. Unfortunately, some of my content was able to "leak out" from this instance to a notorious bad actor instance, even despite that instance having been IP-denied in+out via ufw. However, that instance is behind CloudFlare, and I couldn't deny all the associated IP addresses therein. Just unrealistic. Hence, this journeys towards a (hopefully) better solution with hosts files.
We will see if it works! Time will tell. ---Or, a friendly Fedi user with more knowledge and expertise to tell me that I'm wrong! 😅
RE: https://mtl.jinxian.casa/objects/0194f25a-fecb-0959-a135-14e67b2f7cd9