"I honestly believe that some of the discussions on this subject have clouded a very straight forward operating philosophy."
I agree with the above quote several posts back.
Always said V1 by V1. No "decision" needs be made at v1, no action taken, all you have to do is continue doing what you are doing.....taking off, and if an engine has quit in that very unlikely time between inside the human reaction time before hearing V.....and V1 occurring, then put in some rudder to keep the nose pointing towards the middle at the far end and wait for "rotate". No need for concerns as to whether or not that inbuilt 2 seconds exists and/or is applicable to my airframe type and if it is, does that mean I should/could use it? Christ no anyway but there is no need to "react" to anything anyway. The reaction is sit on your hands, wind the clock, take a deep breath, swear a bit, and continue the takeoff.
The argument here about when to say it is irrelevant, immaterial and beside the point your honour, as the Capt (in my outfit it was always the Captains hand on the thrust levers) you knew when you were approaching V1, and as soon as you heard the commencement of the words V1, you knew that your decision was made - no decision to make, just keep going.
What else are you going to do? "well your honour I heard him say V...... but thought he was about to tell me "Very nice takeoff roll so far skipper" so I decided to abort due to.......and ran off the end at 60kts" No of course not.
No decision to make - its been made for you - GO son go.