At Kai Tak, as at any airport, the go around can be initiated from any point on the approach, just care must be taken to follow the intended track as opposed just following the instructions. By this I mean that a go around initiated prior to the missed approach point must fly over the missed approach point before any turns are made. May sound obvious but I have seen many guys mess it up in the sim. I a situation like Kai Tak there was a seperate procedure for going around after passing decision altitude but it is far too long ago for me to remember.