Having a delay when leaving a zone is great; but I believe it would be equally beneficial to have a delay when entering to prevent people from accidentally wandering into a zone (yes, I have domes) inadvertantly and instantly being flagged for PVP.  It would also prevent poeple from going back and forth into a zone to stay flagged, appear unflagged, and consequently kill someone the MOMENT they enter a PVP zone.

I tried using the "event start delay" but that function doesn't appear to work for this purpose.

I would recommend enabling domes and/or looking at something like https://codefling.com/plugins/auto-marker-pvp-zone?tab=details to make your PVP zones more obvious.