That’s how I ended up using it in discourse-mozilla-iam, PluginStore for storing a couple of global variables which we need to persist across restarts. Full blown models & tables for everything else.
I got around this by setting up an engine in my plugin, and placing the model under that namespace. If any other plugin decides to touch a mozilla_iam_group_mappings table (or MozillaIAM::GroupMappings model), I would be 
That would be 
, I should’ve thought to report it when implementing this slight monstrosity: