@Neustradamus - it sounds like procrastination may have paid off! In any case, I have updated my original post with the steps I took to enable this module using some config variables and the templating system.
It sounds like you’re much more experienced than me on it, so you probably know all of it already and can even point out some places it can be improved.
The main thing I think should be considered in this “update” is to change the 40Listen template. It has some S2S settings in there that are NOT listener related, and it makes it impossible to add on additional templates through the custom template and requires the user to overwrite the 40Listen template in order to add a listener. I could be wrong on this, it’s just my understanding of ejabberd configs and the Nethserver template system.
@dnutan - thanks for the information. Last night I started digging around and remembered that it’s probably configured somewhere in Cockpit, and that’s where the configuration is heading anyway. I was thinking of taking a stab at updating the existing Cockpit plugin for ejabberd, but if it is on the roadmap for the experts then I think it’s best left to them. 