@hemant-ahir
Sorry, I knew I may not be able to explain my problem clearly enough. I don’t want to turn off thumbnail generation globally, only for file uploads for digital products to the woocommerce upload directory.
So the product itself is a photo uploaded to the woocommerce upload directory via the ‘add file’ method in the product creation admin. This photo does not need any thumbnails because it will never be seen front end. It’s just a product that happens to be a photo.
Does that make more sense?