[feature request] Remove seconds from end of video

[githorse]

We have an option to delay the start of the recording after pressing the button:

Presumably this is so the screencast doesn't include me clicking on the Start Recording button.

But there's no corresponding option for the end of the recording, so the end of my screencast is always me fumbling around for the "Stop Recording" button. What about a "Seconds to remove from end of video" option (defaulting to zero so nobody is surprised)?