Thanks for your comments @monet-supply and @MarcZeller. As an update, AIP-318 to freeze MAI/MIMATIC and set LTV→0 has been executed. @thecryptodad no current positions were affected by this change.
Given community preference and to be extra cautious with the risks of MAI, we published an AIP to zero out MAI isolation mode debt ceilings on v3 Arbitrum, Optimism, Avalanche, and Polygon.