When executing a tst file in the DevTest ITR, each time a new step is executed DevTest will steal the focus away from the user.
If a user needs to execute a tst using the ITR, they are unable to do anything on their machine until the tst is finished.
It's easily reproduced:
Create a simple test that will loop or run through several steps
Execute the test
Try to open another application, such as Chrome or Outlook...
Notice you can't interact with the other application.