Bookworm, apologies for quoting scripture to what you admit, was a poorly worded question. BUT, to contend that 'blue line speed' is the defining speed between aborting and continuing a take-off, is simplistic in the extreme. Maybe in your world that makes sense. I would be interested to know how you account for a balanced field length performance calculation involving a critical engine failure at V1 and before attaining best single engine climb speed. More often than not on heavy Quads. the TOSS is several thousand feet further down the runway past V1. How would that affect your stop margin? What would your screen height be at the end of the runway. What clearance would you have with obstacles on your take-off path. If you are unfamiliar with heavy aircraft on wet runways you probably won't see my point.
Lastly Vmca is a very valid consideration with an engine failure at V1 in a lightly loaded A/C using flex thrust for take-off, ie. whether to select TOGA thrust or not.
I think I'll stick to the wisdom of the many performance engineers who have investigated the 'why's and wherefore's' of A/C performance rather than settle for the 'Blue Line' panacea you subscribe to.
If as I suspect you are only interested in light twins etc. then please ignore my rant, because I would be surprised if any heavy metal drivers would be swayed by your argument.