In the non-wuxia world, a punch from a closed fist generally does more damage to an opponent than would a push or slap from an open palm. The physics of the closed fist delivers much more intense impact than an open palm could.
Would the same principle apply in wuxia if a Hong Lung 18 Palms user were to use the same techniques except with a closed fist instead of an open palm? Wouldn't the user be able to inflict even greater damage with a closed fist?
Moreover, is there anything that precludes a Hong Lung 18 Palms expert from turning the palm into a fist (i.e. fire deviation, decrease in power/efficiency, etc.)?