chornedsnorkack,
(a) may I echo alf5071h's observations ...
(b) Logically speaking, using a single V1, or a single other speed decision point, whether V1-15, V1-20, V1-30... means neglecting to take account of how much or how little there is excess runway length to spare
Having selected a V1, the AFM data provides a certification distance for a set of cases - ASDR, TODR (AEO, OEI), TORR (AEO,OEI) etc. It is then a matter of the ops eng (or pilot) repeating the calculation a few times to match the AFM data to the particular runway environment. This can be done conservatively (ie all the cases fit but RTOW is not optimised) or to the optimally limiting case (in which the case the RTOW is maximised).
(c) I think official V1 and BFL numbers are supposed to incorporate pilot reaction time somewhere, setting it as 2 seconds. If you think it is going to be more, like 3 or 4 seconds or whatever, you might try and estimate the results - with accompanying changes to V1, BFL, MTOW
The reaction times vary with the Design Standard version relevant to the particular Type's certification. The specifics are in the individual distance data items (eg ASDR). Particularly with older Standards, the fat is less and the pilot's flexibility (near V1) reduced. If one desires any given time delay during the accel-stop transition, that is fairly straightforward .. but not for estimating ... calculating.
(d) Whereas continuing is a much bigger gamble
Probably we are more interested in risk outcomes than the gamble per se. Regardless, the historicals suggest that your postulate is false in that, for near V1 failures on limiting runways, the probability of an acceptable outcome appears to be weighted towards the GO option. One should also qualify comments by considering whether the case in question is a limiting runway and, if so, which case is limiting. In the conservative case of a grossly non-limiting runway, the arguments can become academic/legal procedural.