When V1 = Vr, it’s pretty simple. When V1 is less than Vr, if the decision is to go, you must accelerate with the inoperative to Vr and V2. In the C-5, we’d do a rotate increase to improve the OEI climb gradient of up to 15 knots. Sometimes 20 knots between the V1 and rotate, a long time at 150 knots or so. The 727 nearly always operated where V1=Vr, as did the Global Express. It’s not a dead man’s zone, just a segment of the take-off where you’re committed to continue. Often, the numbers can be tweaked to eliminate the split numbers.
Yes, V2 is take-off safety speed where a Part 25 has a specified climb gradient, accounting for any obstacles to return or continue.