It would decrease the value on fury for sure if it was lets say.. 'farmed' the armour/weapons you can get from the monster drops on just 1 slayer task can be more then an onyx sometimes.
I honestly don't think this should be changed, sorry.
The monsters in the caves are meant to drop little tokkul to fit that of regular osrs, after all the overall goal is to make it as close to osrs content as possible.