Maybe I have presented it badly, but I will try again.
Consider two airplanes on takeoff with an engine failure for one of them at V1. Up until the engine quits the performance of both is the same. At V1 the all engine airplane and the three engine one both reject takeoff. The only difference will be the reduced availability of reverse for the three engine airplane, and since reverse is not considered, to all intents and purposes the distance needed to stop will be the same. The ASDR will be the same, except that the all engine case is subject to a 15 percent penalty, ie the required runway (plus stopway) for the all engine case is always longer. The case is similar for the continued takeoff; even though the all engine airplane will perform better than the three engine one, it is rarely more than 15 percent better, since only the time from V1 to the end of the TOD is considered.
In my second para, I was referring to the way many new pilots are surprised at the closeness of the end of the runway, as it approaches at 180 knots or so just prior to liftoff. Many have commented to me that it would be diffcult to stop should a problem develop at that point. But the only time it is relevant to check the runway remaining would be at the V1 speed, since a reject is not guaranteed above that speed. The mindset should change to GO when past V1.
Where have I gone off the rails?
LOM, the Vref with Flap 30 is around 140, so I doubt you would have 146 or 152 with Flap 1. But a good point. Must try it in the sim.