What I could get from our FCOM is that for VNAV armed for takeoff it commands the following speed schedule :
1) V2 + 20 knots till all engine accleration height
If an engine failure is detected until reaching the EO accleration height , target speed will be
a) V2 + 20 knots if the speed is at that or greater or
b) existing speed if the aircraft is at a speed between V2 and V2 + 20
Thereafter :
Will command an increase to 250 below 10000 if feed in but will limit it initially to
2) Flap placard speed minus 5 knots ( Flaps 15 and 25 take off's)
3) 230 knots till the time LE flaps are not fully retracted
4) Finally the enroute climb speed after FL 100
More importantly to answer your exact question , the FMC used the EO Acleration information , to ascertain at what height it must start the accleration in case of an engine out scenario .
If it is below that height , it will command a climb at a speed discussed above , when it gets to the height it will begin the accleration .
If the all engines accleration and Engine out accleration height is different , it will acclerate at the appropriate height depending on the case .
I hope the answer fulfills your query .