Difficult to debug a "redirect mismatch error" when an app's callback URL doesn't match value used within client

[jamespohalloran]

It is difficult to debug a "redirect mismatch error" when an app's callback URL doesn't match the value used within the tina-graphql-gateway-client.
In our starter, the site's redirect URL is set with an environment variable.

If the user tries to log in, and this value doesn't match the Tina Cloud app's value, then the user sees a page like this:

I can tell from the URL what the error is, but can we show a more user-friendly error message here, or at an earlier step?