Hi Mark,
This is a great module, I have been using it for a few months and find it great that it handles the different product sizes for UK items, never had this level of control before and is really useful.
Now that Royal Mail are using the same sizes guidelines for international items as they do for mail travelling within the UK is there any chance of getting a large letter options added for international items of mail, I believe that it only affects standard airmail items as opting for tracked/signed for options the price is the same as tracked small parcels.
Also if an item has a minimum size associated with it of large letter then both large letter and small parcel rates are shown, I think this might be confusing to some customers, it would nice if there was an option to have it so that if the item would go as a large letter that only that rate is shown and not both as the customer is likely to select the cheaper option anyway.
~R