NO and
NO.
As
IGh has pointed out, 80% humidity is already "built in" to the certified performance data. No further pilot input is necessary, or mandated. No further input is required by the "user" Performance Engineer who manipulates the AFM data.
With respect to early V1 calls, it may be beneficial for the Accelerate-Stop manoeuvre, but decidedly dangerous for the "GO" case if V1 is Vmcg limited......
NEVER NEVER mess with Vmcg!!!
Regarding the Automated V1 calls, I will be watching the V1 bug with eagle eye on the ASI on my next Takeoff, to see exactly when the "robot" calls it. II DO monitor it closely in any case in case the automated call doesn't come, and cannot recollect any occasion on the B777 when the call was not "spot on".
Regards,
Old Smokey