Hillo Isaac,
Thanks for the feedback! I've added this for an item at our next feature discussion.
Adding auth providers into Firebase is actually a fairly simple process. Firebase Authentication is just a thin wrapper over our
token generators. So you can drop down to that level and
sign your own tokens fairly easily, allowing you to use any authentication process you like.
It does add a bit to the stack, since you'll need your own server process to do the auth and sign the tokens, but not a particularly big challenge if you're versed in server scripts, node.js, et al.
Note that you can skip the RESTful services, and all the server baggage that comes with this by using a
queue strategy.
☼, Kato