Hello I think I know how to use 'Replace by fee', to accelerate a transaction increasing the fee. This option is already running in the GUI of Electrum as far as I know.

Now what about an option to modify a transaction (already sent to the memory pool and pending) sending a new one changing the outputs and increasing the fees so the original transaction is replaced by the newly crafted one, so the funds can go back to the wallet or just go to someone else.

Actually a new transaction with higger fee canot be crafted as funds are verified to be already spent (penfing).

This option could be the last line of defense for buggy transactions just sent to the Memory Pool.

Thank You.