For those (all 2 of you) wondering what happened to my #snac instance, I decided that the limitations while initially well intentioned, were now less limiting due to the scope of the project and features being added over time - meaning it was almost back to a full-featured platform and I might as well be back on something like this.
So #Akkoma was, for me, the logical choice spin up. I see in the documentation it has #ejabberd integration, so might yet utilise that so I can sign into #xmpp with the same account, which would be kinda cool.
I am running both #prosody and #ejabberd for testing and am unsure which I prefer as yet. Possibly ejabberd for the webmin, which is quite nice.