Submitted by Jeiwan, also found by Trust, ladboy233, and cccz
The amounts redeemed in overflow redemption can be calculated incorrectly due to incorrect accounting of the outstanding number of reserved tokens.
Project contributors are allowed to redeem their NFT tokens for a portion of the overflow (excessive funded amounts). The amount a contributor receives is calculated as overflow * (users redemption rate / total redemption weight), where users redemption weight is the total contribution floor of all their NFTs and total redemption weight is the total contribution floor of all minted NFTs. Since the total redemption weight is the sum of individual contributor redemption weights, the amount they can redeem is proportional to their contribution.
However, the total redemption weight calculation incorrectly accounts outstanding reserved tokens (JBTiered721DelegateStore.sol#L563-L566):
Specifically, the number of reserved tokens is added to the weight of minted tokens. This disrupts the redemption amount calculation formula since the total redemption weight is in fact not the sum of individual contributor redemption weights.
Two options can be seen:
drgorillamd (Juicebox DAO) confirmed 
Picodes (judge) upgraded severity:
