Well not really,but off late this does seem to divide most bikers in the Indian Royal enfield community and get them all riled up!
I have just replaced my Cast iron block with a aluminium one.
There are a couple of reasons for doing this.
First of all it happens to be much lighter than the stock block ,about 3.5 kg lighter in fact!
Since the supercharger weighs in at 7.7kg it will negate some of the weight added to the bike.
Secondly the heat dissipation will be better than stock.
This is beneficial especially when supercharging, as for every Psi of boost used there is a increase in heat generated within the engine proportional to the efficiency of the supercharging system.
So in my case I haven't killed the old CI block, I have merely retired it for a bit.