Well an executor must provide an account to his beneficiary. There is no set format but should be as detailed as possible.
I would suggest you send the beneficiary the accounts and asks he approves them before you send the final balance. If he refuses to approve them and request further info you will have funds out of which to bear any costs. To be fair if he really wants bank statements copy them and send them.
Sadly you can't charge for your time but your accountant can.