How to turn off record highlight feature?

How to turn off record highlight feature?
I believe it records everything in the background, and then, when I press the button it cuts part of that recording, right? But that background recording should reduce my fps and I would like to get rid of it. How to do it?

You can't turn off Overwatch highlights.

It actually doesn't seem to record full footage in the background from what I understand. Apparently, the Highlight feature can produce footage at a higher resolution and frame rate than your system can provide. This leads me to believe that instead of recording the complete screen in the background, it actually retains a deterministic representation of the past 12 seconds. When you decide you want to use one of your 3 highlight slots, it just stores this 12 second representation and doesn't actually change it to a video until you ask it to, using the settings you provided. So the highlights feature shouldn't actually have a noticeable effect on your system performance.

In addition, the highlight recording happens on the servers, so it shouldn't have any impact on your PC performance.