I just discovered that the pack of shortened card sleeves I've been using for Vault and starting item cards are made by BCW, not UltraPro. They're still 41x63 mm, but there's little to no overhang at the top of the sleeve.
As for why I'd use these, it's so that if those item cards get shuffled into the deck, it'll be easier to find them (especially useful in Modern Zombicide since the Molotovs and Pimp Weapons are the same color as the regular item cards).