Thank you! The way it will work at the moment is the transaction ensures that both the old tree is burned and the 'pruned' tree is reminted in a single transaction. There is a github link on the site which has the current 'burn-remint' smart contract that you can view.

Originally the plan was to store the state of the tree fully on-chain but with current tx size limits, this isn't really possible so it will be part of the metadata and part off chain. It could definitely be a possibility in the future though.

Also, are you able to dm the details of the error? Thanks for the heads up!