I disagree with this, though I have an alternative;
Instead of having double drop rates, I'd like to see double drops -> which means the NPCs drops 2 items instead of 1.
e.g. The Zamorak boss is possible to drop 2x the same item or ofcourse 2 diffrent items. (you need to be extremely lucky to get 2x a rare drop)
This is not during double experience, this would be a nice little extra after having maintence problems
Correct me if I'm wrong, but let's say this boss has a 1% chance to drop his rare item, one person kills this boss 100 times.
So this person will get the rare item once in 100 kills, with your suggestion this will grant that person that item twice.
With the initial suggestion, the boss now has a 2% chance to drop the item, after 100 kills, this person also received the item twice.
So basically the amount of items entering the economy will remain the same, further pushing prices down. I heavily disagree.