The HST when full, only extends range by approximately 45 mins in cruise i.e. increases range by up to 450 nms. Although the freighter is not fitted with the HST, I am not aware that the PAX version was available without it. Perhaps a Cathay pilot with 747-400BCF experience can verify whether or not the HST is usable on this version? It is my guess that range for the freighter is not as important as trim and the possible restrictive effect that a full HST may have on loading.