Writing the answer to a query takes about ten minutes. That is never where the cost is. The cost is the three days spent finding out which claim the query belongs to, digging the file out, working out which doctor can answer it, and then catching that doctor between operations.
Meanwhile the fifteen-day window is running. Most claims that die on a query do not die because the hospital had no answer. They die because the answer arrived on day sixteen, or because nobody noticed the clock at all. The fix is not a better reply. It is knowing on day one exactly what is being asked, of whom, and how long is left.