I was looking at Liquity's redemptions, basically, a caller pays 50BPS+ to redeem collateral. So I was thinking, the person that got the CDP closed, could just re-open, but by doing that they are dumping LUSD back in the ETH pool (assuming ETH-LUSD is the main pool). This seems to mean that redemptions only work if people don't re-open, what's a better mechanism for protecting downward depegging?