Check doc 8168, you should find there some refference stating that initial departure HDG within 15 deg of RWY HDG are considered straight departures, in other words not requiring a turn.
The way to deal with it which I believe is commonly accepted is that as long as it is within 15 deg of rwy hdg you do not wait to 400' in order to turn as in the case you were stating.
If it is over 15 degrees off the rwy hdg then you wait till 400' or whatever your company SOP/OM specifies.
The 400' is actually 394' as per doc 8168 if one wants to be precise.
Forgot to mention, this info comes from definitions of SID's on doc 8168, which means no TURNING SID (turning as in requiring more than 15 deg turn) should require a turn of more than15 deg off the rwy hdg till 394'.
Being that the reason why you should not see any waypoint requiring turning <394' as our colleague FlightDetent pointed out, at least that is the way I interpret it.