Are you holding because the weather is below landing minma?
or
Are you holding because the weather (while being above minima) is causing a slow down in movement rates?
IMHO if it is the former then the only fuel that can be used to continue a hold is the extra fuel above that required to reach laternate and land with the final reserve.
If it is the second, then I think that there are situations where (separate independant runways etc plus weather above minima), where the flight can comitt to the destination and then the fuel requirement is to land with the final reserve.
Just a stab in the dark, so perhaps someone can confirm the above theories?
Regards,
DFC