Instant view is obviously not the issue, as they are allowed to have binoculars. It seems to me that any advantage would be in being able to rewind, and in examining a full sequence of signals, repeatedly.
I agree that being able to learn from the recorded sequences is likely the primary use for this, but once signals were decoded, don't you think the ability to see the signaling in real time without having to verbally relay it might help as well?
Also, I wasn't aware that binoculars were allowed. Are they allowed in the booth and at field level?