The only real advantage is shorter spoke length, which makes for a marginally stiffer wheel and a negligibly lighter one, neither of which I think is worth it (even though I do like rear wheels that are 48h 3x which is noticeably stiffer than 48h 4x and 36h 3x)
I think you're referring to the number of spoke crosses in the lacing pattern, eg 2x, 3x, 4x? I'm referring to where the spoke holes are relative to the rim's centreline rather than the number of spoke crosses. Rims like federal stance XL, eclat Bondi, and plenty of others have the spoke holes significantly off centre towards the side of the hub the spoke will be on. The opposite of cross lace rims like GSport.