@Tommen If I get it right, you need something like conditional Navigation.
I am using a true/false field in my user collection to deactivate a user if necessary.
On the login button I am using to actions:
using conditions (Click SHOW ADVANCED):
If the user is flagged as deactivated he is linked to a screen with a short information and a button where he just can logout.
In case everything is fine (user not deactivated) the link goes to the Home screen:
Note that you can add another action to update the user, where you e.g. can toggle the true/false field
Hope this helps.