If the use of an intersection lowers the V1 to below balanced field, without any other gain, then I defy anyone to come up with a good explanation as to why that is good airmanship.
Runway behind you is just as useless to a heavy as it is to a lighty if the V1/VR split is 20 knots! ( or whatever figure you care to pick )
As was mentioned previously, the figures in the book ( albeit with good margins ) are arrived at by test pilots, not Jo Average ( or below average ).
The amount of RTOs that turn into runway over runs/accidents is quite alarming, regardless of the reason.
At the end of the day why would you want to reduce the safety margins for no gain ?