Max fills in a token's whole balance, or for ETH the exact balance minus the fee reserve the confirmation screen's balance check gates on. The confirmation screen works a max ETH amount out again from its own fee estimate and signs it with that estimate's fee fields, so a fee that rose before signing cannot push amount plus fee above the balance. validateTransfer() still gates every send, the check that ETH covers a token send's fee included. Where there is nothing to fill in, a flash message says why. Model: opus-5-5