The plugin's performance when processing database data has been optimized. This update requires sustained feedback from the community, as I, as the author, don't have that many "players" to test it with.
Added not-open-when-invalid option support in buy more menu settings in config.yml file. If there is only a purchase button in the buy more menu and the product is not purchasable (meaning there is no buy price), then we consider this buy more menu to be invalid and cannot be opened, and the same applies to sell.