It wouldn't hurt to rotate the stock a little more often. I've seen Strange Allure, Chronicle, Howl at the Moon, Honor Guard and many more in the store for over a year now without ever being rotated out with different outfits. I already own a lot of these.
While I appreciate that they do add a couple different 'limited time' outfits every few weeks, with literally hundreds to cycle through, it would still take years to get through them all.
Simply rotating in/out a larger portion of the Hongmoon Store outfits can't be that labor intensive.