Honestly, mihoyo should at least allow for duplicates of characters you own at least (and also at least and I do mean AT

Honestly, mihoyo should at least allow for duplicates of characters you own at least (and also at least and I do mean AT LEAST the 5 star ones you own sans the MC) to be available for purchase for upgrades in the shop, either via primogems or on the other currency you get specifically by doing the wishes because pulling for 5 stars for F2Ps is already a chore (and not just because of luck but also the primogem grind), let alone pulling for duplicates for constellation upgrades.