Just released, open for testing, if you BIND with your OPNSense and Docker (w/Portainer), this might be of interest!
As I have ran my own internal BIND DNS setup for a while, and did not explore the built-in that OPNSense has (wanted to learn-it-all), and then wanted to resolve IPv6 for my network this became an eventual desire and then creation. It uses the OPNSense API as well as the Portainer API, then directly and securely interacts with BIND via TSIG.
Please feel free to check it out, comment, or even suggest how else one would do the same in a different way:
Homelab DNS Updater (Github) (https://github.com/j0nny55555/homelabdnsupdater)