Edit: should make a clarification that you mean jewelry boxes you find while thieving, then yes I support that as it would make sense and give more incentive to thieve
Actually with Jewelry Crafting a possibility now, i really think Jewelry boxes should contain a random piece of jewelry, or the possibility of a JC trait stone, or improvment mat. Anything to help make the grind a bit less painfull.
Specifically, i'd love it if pots and urns had better loot. Not much better, but getting so many 0 value gauntlets and belts is fairly annoying and unrewarding.
"According to the calculations of the sages of the Cult of the Ancestor Moth, the batam guar is the cutest creature in all Tamriel"