Restore only data of one app

[h-h-]

Imagine the following scenario:

The data of one app are destroyed. The app crashes each time it's started because of the bad data. All other apps work fine. They and their data mustn't be changed.
To recover the faulty app, I want to go back in time step by step until it no longer crashes.

How can I (temporarily) stop Seedvault from making further backups of this app - but keep all existing backups?
How can I restore the data from an earlier point in time for this app only?
Can this be done from the UI?
How many versions of the app's data does Seedvault keep?

I think this should be a basic requirement of any good backup software.