Plus 4 Nozzle Choice - BiMetal Hardened Tip Vs Tungsten Carbon

Just about to hit the button on the Plus 4 and note that it ships apparently with a hardened nozzle, yet there is an option of a Tungsten Carbon also?

Is the only difference that the tip of the shipped one is hardened Vs the TC one being the whole nozzle? Just wanted some clarification please.

Anything I should include in the current sale to add in, second plate or something else?