Surveillance is clearly meant to be a perk that promotes generator patrolling, it just doesn't do it very well. So I have an idea on a rework.
The noise of survivors working on generators is increased by 30/40/50%. Additionally, your Terror Radius intensity is reduced by 40/50/60% when you are within 32m of a generator that is being worked on.
I found it kind of difficult to think of what to do to improve Surveillance but I feel it should sort of be the reverse version of Technician on the survivor side. This rework allows you to hear generators at further range if they are being worked on and allows you to launch more of a surprise attack on them with the muffled Terror Radius.
NOTE: Terror Radius "intensity" is NOT the range of it, but rather how loud it is as you get closer to a survivor.