Set user role programmatically?

So now that SWA is in GA, are we still restricted to 25 users in custom roles? The docs still say this?

What I'm wondering though is if it is or will be possible to assign users to roles programmatically? Logging into your Azure portal to generate an invite is ok for testing purposes during preview, but in production this obviously wouldn't scale well.

The scenario I'm thinking of is a web app that allows users to sign up for free, but then also has a paid subscription. A free user is automatically in the authenticated role when they sign up. However when they start a paid subscription, they are added to another role to allow for greater access to the app beyond just an authenticated user. Surely there is some way to add them to another role programmatically?