I daresay that the set of airlines sees approaches to performance scheduling ranging from
(a) ignoring everything other than runway length data through to
(b) a complete analysis of escape paths to a point where the enroute phase can commence with full attention to obstacle clearance throughout.
HSWL quotes a figure for height and distance.
Consider that twins, for which the V2 to clean speed split is significant, can see something in the order of 40-50 nm to complete the takeoff through to enroute phase ... sobering, is it not ?