In Season 13,
Persona Assistant (2019), Stan similarly uses Roger's outfits to appear as Roger's personas. However, for it to work he had to wear a Skin Suit underneath to add this alien property to the clothes, to "hide" Stan and allow him to appear as each persona. Here this aspect is in the outfits themselves.
Although it's conceivable that Roger has somehow changed the outfits to carry the quality inherently now, he has no motivation to do so (the outfits work with him already, and he has no plans to have humans take over for him again), and he has seemingly thousands of outfits he'd have to adjust, rather than the Skin Suit which simply worked with all outfits.