@spencer this post talks about upgrading to 1.44.0 or later, but 1.44.0 is not actually released yet? Right?

Each of the applications that I intend to create registrations for already have their own identifiers. I suspect this is very common.

After authenticating my user, and confirming that they have an active registration to use the target application, I then need to know their corresponding "application account ID".

For example, if my application is "bank account", I need to know which "account number" is owned by user@example.com

From the docs, my understanding is that the expected/recommended way to handle this is to store the account number in registration.data like:

{
  "account number": 12345
}

And maybe I also declare that they're a primary account owner via roles.

I saw in the docs that a JWT includes roles within its payload, so I can easily find out that my user@example.com is a primary account owner of my "bank account" application - but what is the recommended way to discover that they own "account number 12345" ?

Do I literally need to resort to the registration API?