atm you need to add code via https://community.bistudio.com/wiki/setWaypointScript (unless I am missing an alternative)
a group EH would be way more flexible. and just for situation where its the last WP with SAD/SENTRY/DESTROY that timeout eventually (and you want to repeat them)
it could also may the SUPPORT type useful that way (its one off-use only and AI gets out of the support vehicle upon completion) [pretty sure in OFP that wasnt the case - you could call them via radio menu again and again. was very helpful on tank missions]
or if a MOVE WP times out (usually with vehicles but also infantry can get stuck)
parameters: _group // ref _waypointType // string _waypointIndex // int _lastWaypoint // bool return: _timedOut // bool - false if WP condition was met; true if WP type timeout hit instead (int instead of bool if there can be multiple reasons for a timeout?)