Apperently the IOC button suppose to be greyed out because that function is now in the new intelligent navigation options as Home Lock.
Yes the waypoint function doesn't seem to be all that, apparently you need to fly manually to your chosen waypoint before you can save it as a waypoint, so you can not chose the waypoints directly from the map.
But the waypoint route can be saved so next time you want the same route you don´t need to fly it manually to the waypoints.
This is done for safety according to DJI.