As others have said, there's judgement involved. Consider that continuing the takeoff allows for EF recognised at V1 - so, in the highly likely event that you retain all engines, you do have some margin (even BFL) if you continue. Consider margin between your normal liftoff speed and Vmu, Vs and V2, availability of additional thrust if using flex/assumed temp, or even fixed derate in this case - i.e. windshear = firewall thrust. It's also true that in many situations, if you reject above V1 you will stop before the end of the runway (how often are you right up against your RTOW on a long runway?, consider factoring of wind and allowance for pilot technique). Judgement and SA.
The guidance that springs to mind in this instance is, delay rotation until no later than 2,000 ft from the runway end. Seems like in most situations continuing would be the most appropriate option.