John, it's all about payload. The point at which an operator MUST account for an engine failure is at Vef. From that point, either the accel-stop must work, or the accel-go must work. In most jurisdictions I'm familiar with, the requirement to absorb an engine failure part way through a normal departure is grey to say the least.
Most special special engine out routings include a point of deviation from the normal operations SID. There are not infinite points of egress from the SID routing to the engine-out one. While we often believe that the point where the two routes split is the point at which an engine failure can be handled on the SID routing, there often is nothing to shore up that belief.
But this question was regarding a simple, normal takeoff. Do you know you can meet the published gradient with all engines operating? The answer is, unless you have specifically looked at your all engine performance beyond the altitude specified in the SID, you don't know. The criteria for one engine inoperative takeoff are not linked in any way to the SID design.
Muddy enough?
Cheers
Vs