I really like to use filereader Uploader mode. because the process is instant.
but not everyone has a fast internet connection, while using Uploader filereader mode. when clicking add to cart, often people are not patient
and will think that their connection is problematic, because the two types of the popular browsers i use, like chrome only have a small indicator at the bottom that is sometimes not visible / not realize. even in Mozilla none at all.
I do not know if there is a trick to add animation during the upload process, but it would help if the FPD has it.
No sorry, this is not possible. I will also remove the Filereader in the next big update because its not good for large images and take a while until the item is added to the cart.