Make blast furnace reject leather armour.

I propose to add the following feature to Minecraft.

The blast furnace should reject any leather armour placed into its top slot, in the same fashion that it rejects non feuls places into its side slot.

This feature would allow players to automatically sort leather armour from metal armors in mob grinders. To allow players to make use of the armour smelting feature that many consider useless as there is very little effort to reward ratio.

Changing only the behaviour of the blast furnace in this way I feel adds to the game without majorly changing any other game mechanics and links nicely with already established features