FAA/JAA rules dictate that all take off data must be based on the most unfavorable CG position, FWD limit.
Reduced negative lift from stabalizer (less ANU trim setting) due to aft movement of GC location leads to:
Stall speed reduction and V2 reduction
Reduction in trim drag associated with less THS setting, less ANU.
Reduction in TO limit speeds.
All of the above improves climb capability and reduces TO ground roll.
Taking credit of this advantages, better ground aceleration and improved climb,a B767-300 could increase its RTOW up to 2.0 tons if its CG is located aft of 20%MAC (FWD limit is 11% for a 184 MTOW), "trim drag" is reduced 2%.TO speeds must be increased 2-3 knots.
REGARDS.