Hey there!
It’s been some months since I last replied to any topics in this forum, I’m sorry about that. Hopefully no one missed my responses. 
(Sorry, Orne, I switched jobs and have been terribly busy).
Anyway, I’m reaching out exactly for that reason: I’ve been lacking time and I could use some help maintaining my Mosquitto auth project, which some of the folks here seem to use. Since the usual go-to plugin was archived some time ago, it is now the kind of default (citation needed) plugin for Mosquitto auth purposes (which could turn out to be not that relevant since Orne added support for RabbitMQ on some parts and may continue to do on the missing ones, but still). Like this project, it’s written in Go, so anyone who’s messed around the source code for the once named loraserver project should feel just like home when contributing, which of course is what I’m asking for and very welcome!
Many of the basic bits were written when I just started learning Go, so there’s a lot of space for improvement and refactoring. On the same line of thought, it supports a bunch of backends, but there are many I haven’t implemented yet and a lot more that I don’t even know about that could may their way in.
That’s about it. If there’s anyone interested in this, just respond here or DM me.
Cheers!