Do Until loop actions seem to resolve in "Success" if they either.
1. Meet the condition
2. Reach the defined loop count limit
3. Reach the defined timeout limit
However upon exiting the loop I don't think it's currently possible to determine why the loop exited and configure action accordingly. It would seem to make sense to be able to configure a Run After "Timeout" action when the loop exits due to hitting it's timeout limit. It would also be great to be able to do the same for it hitting it's count limit threshold.
This would help when managing things like waiting for a sharepoint document to be checked in or a status to change.