Why flying fast on Improved/Increased V2 after an EF is dangerous - particularly when limited by a close in obstacle - and even more particularly when using wet figures.
While concurring with OS, perhaps the question relates to flying faster than the overspeed schedule calls for ? In this case
(a) screen will be achieved further along the runway which may compromise a variety of limits in the calculations.
(b) alternatively, if the speed is allowed to increase during the initial climb, the short term climb gradient will be compromised significantly.
(c) the potential for conflict with the early obstacle is obvious if either (a) or (b) applies. The basic overspeed calculation, however, will have addressed the obstacle and provides no inherent hazard greater than for a routine takeoff.
For a wet calculation, (b) is similar. However, due to wave and impingement drag on the runway, (a) might be VERY much more compromising and, in a limiting case, might see the aircraft not achieve the higher speed presumably chosen by the pilot on the day in violation of the prescribed procedure.
In general, unless one knows what is going on and has a very good knowledge that the procedure is going pear shaped, it is far better, on the odds, to follow the declared procedure.