I know many pairs who have tried to switch the balanced ranges in the 2C opener and the direct 2NT opener.
I'd be interested to hear what hand types are considered the most important for responder to describe after the 2C opener.
I assume 2D and 2H as 'transfers' maybe promising the transferred suit or maybe not.
2S to force either 2NT --to get back to 2NT structure -- or to puppet 3C....
and 2NT+ as minor-suit oriented hands/oddball three-suiters?
Or is some other structure better?
Plus... it's free!