I have a hardwired Ring Doorbell. When I get a notification of a button press, the recording starts at that press. I would like it a lot if the recording began sooner, so that I could see the delivery person drop-kicking my package and then ringing the doorbell. Since there is time travel, the doorbell would have to be recording to an internal buffer (which is fine for my wired doorbell) and then use the N-seconds of video prior to the button press.
This would also be great for motion-triggered events, too. For example, a car pulling into my driveway but not setting off motion, leaving a vandal or thief, then driving off. The vandal/thief sets off the motion and the recording includes the car. Many of my motion-triggered events start with the person walking AWAY from the camera instead of approaching it.