Storing $result in $form_state

In the mailchimp_signup module, the form that submits and saves the subscriber submission doesn't actually save the results to form_state. What I have is a block version of the signup form with just email, and then I have a full page version of the signup form will all data.

What I'd like to do is a custom redirect after submitting the block form that puts them on the full page, pre-populated, and acts as an update form in case they'd like to add more data.

I know there is a hook for "mailchimp_subscribe_user", but that doesn't give me the data in the form context so I would have to grab it from the hook, save it to a session, (or something) and then use it in the next form.

Maybe there is another way to do this? If not, I have a small patch.

Speaking of 'mailchimp_subscribe_user', I noticed there was nothing in the mailchimp.api.php file as of yet, so I have another patch for that if it helps.

Thank you!