... the generation of the transaction is handled onboard the wallet. the only information exposed to memory, to the best of my knowledge,
No, the transaction is created in your software wallet (Ledger app or Electrum etc). It is the SIGNING of the transaction with the appropriate private keys that happens on the hardware wallet.
Anyone of you that has a Nano and can confirm that it displays transaction info upon PIN request ?
And to answer the OPs question... yes, it displays the address and amount and you have to confirm it before the transaction is signed and returned to the software wallet for broadcasting.