SABNZBD has always been a problem for me in servers since it doesn't have a GUI-based upgrade method.
It also seems that OMV doesn't have a way to do this with the plugin upgrade, I'm still a version behind.
Is there a trick you can do with SSH or something to shut down, upgrade SABNZBD's code, and restart it, to be on the latest? GUI (like CouchPotato offers) would be best but I don't think this is possible in SAB?