Since the JS SDK already implement all the Metaplex-related operations, we could create a Metaplex-wide CLI that simply adds an interface layer and immediately delegates to the JS CLI.
Something like that:
mplex nfts create
mplex nfts update
mplex nfts find-by-owner
mplex candy-machines create
mplex cm create # shortcut
mplex auction-houses create
mplex ah create # shortcut