I respectfully disagree.
. Except in a special case e.g. you need to quickly stop the enemy before they steal the magic items. If you do it in 2 rounds you keep 5 items, 3 rounds save 4 items etc then a biggrr reward (gold and /exp) can be effected by time
In most quests how you do it or how long it takes should no effect on exp.
But there should be some missions that are timed.you have 1 day to stop the queen from being poisoned.if you do a full rest then need a few short rests you cant complete that mission. In fact if you rest at will without risk it will be like DOS2 using a bedroll which breaks resting which is a core mechanic of the game (i.e. saving spell slots/skills) for the boss fight.
