When posting a transaction (either manually, download, or batch change) you should be able to set a specific value against a specific payee.

e.g. Sainsburys, Sainsburys Smkt, Sainsburys Local
They all fall under the single branch of "Sainsburys" with probably a single category entry of "Groceries" (or something similar).

I have set up an address book entry for Sainsburys, but there appears to be no way to batch change all my entries to the address book value. See attachment where two have been manually selected by the dropdown (Payee - I don't know where that second entry is from unless it's the last entry, but the automated option should be to the payee not the previous transaction - or have a config for that).

By default, entering the word "Sainsburys" in a manual entry, it should match against the Address book value and automatically link.
Rather than needing a mouse click when you are typing and pressing tab to go through the fields. (auto_payee)
This would then allow for a report by Payee to be created.