Gnow, I suggest that if you want to tie this down, you just require the airspeed to be above Vtoss before actioning the fire drill. If coming off a rig you clearly don't want to shut down the engine until you reach OEI climb speed, and getting to that speed and starting to climb is the critical flight period. After that, what difference does it make whether you are at 200 or 100'? The aircraft will be flying itself, and carrying out the fire drill on the wrong engine would be a disaster whether at 100 or 200'.