Stream integration: camera.record lookback

I seem to have properly integrated my cameras as I am able to call camera.record. I have “ticked” the preload stream for each of them in Lovelace.

My question is with regards to the lookback attribute; is there a maximum value for this? I have tried 5, 10 and 30 for my cameras, but am not seeing any difference.

I’ve set the lookback to 2 seconds, and the duration to 15 seconds. This gives me a 47 second long recording, with the event happening after around 30 seconds. So is this a bug? Has this ever worked for anyone?

I think you must have played back the stream at least once, or the lookback does not work; i work around it by playing it a little on a dummy player, see my post here: Toggle entity options (Enable Preload stream option for camera entity) - #4 by flowby