The OPT does provide detailed margins in the Acc-Stop scenario, i.e. how many meters remaining if you must stop. The Acc-Go scenario is a bit more complicated, but IIRC it'll tell you the limiting factor (field length or obstacle normally). How many inches will fit under your boots is a guess only.
Apologies to those who do use these numbers as a reference, but my experience says those numbers are never looked at, let alone acted upon, in this particular airline. Whatever the computer says, goes.
I understand it wouldn't change things in this particular take-off as full thrust was likely already selected, but it's worth thinking about.