The main point of profiles is to be able to quickly fill in all the required fields with standard values when creating new listings. Once your listings are already created there is no need to apply a profile. If you want to change some value or values (price, title, quantity, template, etc.) for multiple listings at once you can use our Bulk Edit or Find & Replace tools located as buttons on the saved listings page. Hopefully those tools can provide the same effect you are looking for.