This has been suggested countless times.
Here is the problem; with the current clear lag system, you lose items even if you JUST threw them.
I know someone is going to say it: "Just be more careful, watch for clear lag"
The problem with that logic is that we shouldn't have to worry about our items disappearing the second we drop them. So no, the solution shouldn't be "be more careful" when the server has a system implemented that when items are dropped, they can instantly be cleared.
Now to the better solution, and my suggestion; an item timer that clears the items at so many seconds.
This could mean an item disappears after 2 minutes of lying on the ground, and solves all of the problems with the current clear lag system.
I believe a solution to the problems of our current clear lag system; such as this suggestion, should be a high priority.
It is bull poop that we can lose items because of clear lag when there is a better solution we don't have implemented. At a bare minimum I'd say it should be refunded, but it's not. (And with prism, you can tell if someone dropped something at the same time as someone else, and if they didn't pick it up and then the item disappeared, staff would know).