Hi Jon,
I have heard back from the team and we're very likely going to be moving away from that particular membership plugin and will be using a more mainstream/popular plugin to manage the membership aspect of the site. So, it seems like the Proof of Concept with a bit more tweak (i.e. domain check) will work for us, and hopefully, for the other users of the plugin too.
Let me know if you need anything else from us to finalize things.
Thanks!
Bowo