This raises an interesting question that is conveniently ignored...
Many people advocate extending the second segment on curved escapes if the final heading hasn't been reached - ie don't accelerate and turn at the same time.
This philosophy makes it slightly easier to fly - turning, levelling off and accelerating is a handful for some, but it invalidates the RTOW chart.
By the way my company uses 800 ft for classic 737's and 1000 for NG 737's as the acceleration height. We have 5 min engines on the classic and 10 on the NG.
THe RTOW charts are predicated on the above acceleration heights and engine time limits.