I think it would greatly benefit player customization. While there are tons of great designs right now, some of them are matched with debatable edges (such as death with solid ones and not thins).
This would also allow for much more mix-n-match and the easy introduction of new borders, allowing for even more combos.
poison shark, white eyes and obulus sail slot combo (probably, i dunno i dont pay alot of attention to sail patterns)
optional: extra vanity slots gamepass could also unlock more combo’s/it could be a seperate gamepass