Today, when a dapp calls eth_sendTransaction, the parameters are sent up to the signer, and the app is called back once, with the resulting transaction hash.
This is a great way to allow a dapp to track the progress of a signed transaction, assuming that transaction is static and not mutable.
Recent transaction backlogs have forced us at MetaMask to add a button on long-pending transanctions to "Retry with higher gas price", but if a dapp or service was tracking the signed transaction by hash, it has no way of discovering that this transaction was ever resubmitted successfully.
This is only a problem for apps that submit a transaction, and continue tracking that specific transaction hash until it is mined, but for dapps with that problem, one solution could be to add a new method, maybe called eth_sendMutableTransaction, which calls back not wit
