I feel like if i'm practicing kongs off my weaker leg, i'm wasting time i could be practicing kongs off my stronger leg. The only reason i trained my 'dark side' (tricker term for non favored side) for kongs, dash vaults, and speed vaults, were to teach people that do them that way.
more practical moves to learn on your dark side are lazy vaults and tic tacs, because i run into situations where i need to tic tac/lazy vault on my dark side often.