Why not just use their Upvato? The automatic uploads are directly from their accounts. Nobody is going to turn over those accounts because they have clients that they have to support.
Most people who get these GPL plugins do it to test them out and then buy them from places like Envato. This is because is the only way people can test them out to see if it works as its supposed to.
Sites like this are great to actually see if the product works or not. This site has actually increased my purchases because I can totally recommend a plugin or theme to a customer without getting burned with a plugin or theme that does not work for the customer.