So what gradient can you make? You really ought to know the answer to that one. And the second question, what would you if you have an engine failure following a go-around when using the lower MDA? I'll tell you what we would do and that's to follow the non-standard N-1 procedure that you would use following an EFATO (and not the Standard Missed Approach as depicted on the approach chart). The rationale behind this is that the point where you start the go-around (before the start of the runway) will give you a distance bonus vs the take-off scenario. You'll also have the additional bonus of flying speed before the start of the take-off point.
Now which minima you use is your choice but at least you have an argument for using the lower minima.
PM