Hi, thanks for the question.
For the core AMM/DEX, the contracts are not upgradable. V2, V3 have always been this way, which creates assurance to users that the LP functions cannot be upgraded and LP funds cannot be exploited via upgrades. We intend for future upgrades to follow the same principle.
I don’t think that affiliate DEXs necessarily need to use PCS’s DeFi codebase entirely. As the proposal above acknowledges, some of our products rely on external partners. Therefore, for these products, we think that affiliate partners should use other contracts, some of which may be upgradable. We will keep a close eye on these, but generally we will try to partner with teams that we’re comfortable with.