Safetypee - thank you for the fascinating reading.
Tourist - regarding your idea of a dynamic V1, I agree it is technologically possible. The main question any good analysis would ask is is it worth it? Perf A does not exactly provide massive margins at the moment (look at wet takeoff performance on a limiting runway for example) so I fundamentally don't see there is much more than an extra few hundred kilos of payload to get out of it.
In contrast, the additional risks from cutting margins entirely to the bone is in my view not warranted. Why would anybody waste billions of dollars certifying their dynamic stop-go aid when they could just program HAL with Perf A?
There is a small subset of types and fields where it may be useful - I have operated bizjets capable of sub-1000m landing rolls off 3000m runways, and am well aware that the aircraft could safely be stopped past V1/Vr (as the two are normally the same) given one has 1800m of runway still ahead as one rotates. This is generally less likely to be the case for medium and heavy jets though.