I think this values are limited by the amount of ram in the camera, at least in regard to whats saved from before you press event button ( prebuffer )
What come after should in my book be irrelevant and could be any amount of seconds/minutes.
I am hoping newer dashcams will go by actual video file being made in the moment, and then depending on where in the ( say 3 minute file ) you press the event button then the file ( 3 minute ) before it is saved and the current 3 minute file you are on, and if you are really close to the end of the current 3 minute file then the next one might also be saved.
This way in worst case you will get 3 X 3 minutes tagged as event files, or anything else depending on the file size you use.
This way camera ram is of no use as its not what can be in memory thats saved / prebuffered, but it all relate to the actual files being made and where within ( timer ) you are in said files when you press event button.
Off course for parking guard you will need the ram in the camera, but for manual events i cant see why the camera should not be able to tag files already made or being made now or really soon as event files.
The 15 seconds are pretty stupid in regard to manual event as you have to get on the button real fast, and by doing that be a traffic hazard yourself
