This issue is more simple that it first seems.
Generally, the procedure designer will select a missed approach that requires the minimum climb gradient.
Even where there are no obstacles in the missed approach area, the standard minimum climb gradient is 2.5%.
So with no other factors one expects that the procedure designer has already selected a missed approach routing that requires the minimum climb gradient even if this is greather than 2.5%.
However, in some cases, ATC, airspace and other issues can prevent the route of least obstacles and the actual missed approach area is designed over an area of higher obstacles.
In this case it would be possible to design a missed approach procedure for emergency purposes that avoided the higher obstacles.
This procedure could not simply be the OEI take-off route since the dimensions of that are different to a missed approach area, the obstacle clearance requirments are different and while on lift-off the aircraft will never be more than 1/2 runway from the centerline at the missed approach point it can be much further depending on navaid accuracy etc etc.