It seems strange to show some of the required common fields (like Fee) but not others (like Sequence) even though both are auto-fillable. The other transaction references are somewhat inconsistent about how much they provide of common and auto-fillable fields, so that's also something we should try to improve. IMO we should provide everything except the fields added in signing (so include Fee, Sequence, and Flags but omit SigningPubKey and TxnSignature).

Also, ideally, we would add a {% tx-example txid="(hash)" /%} tag for the new transaction, with an example from Mainnet (since it'll never be reset, so any full-history server will be able to find it forever).

It might be easier to submit such a transaction yourself rather than trawl the ledger looking for one. I did write a quick script to find and display transactions of types we don't have examples of, but it hasn't found any MPTokenAuthorize examples... yet.

Fantastic!