The ability to make a dispenser drop items instead of placing them (e.g. boat, shulker, minecart, tnt, etc).

Problem:
I am trying to change change shulker behaviour whereby only specific shulkers spawn a shulker block and others just drop the item. Default behaviour forces shulkers to be placed as a block.

Proposed feature:
Something similar to an event.setItemDrop(boolean) and an event.isItemDrop(). This would, instead of default behaviour, shoot out the itemstack when set to true (similar to a dropper) and by default be false for; shulker, boats, minecarts, tnt, etc.