Block ip address
That's a tricky question
Honestly I haven't tried it yet. What you can do is you might consider trying this for a day or so and then see what kind of impact does it have on using Ad Preview Tool.
As per my understanding if I go by the logic of using IP exclusion tool, ads are not shown to the excluded IPs, but that's for live ads and I am not exactly sure how this will impact using Ad Preview Tool. So best would be to try and see and let us know here how it goes.