You’re probably not going to get this question answered on this forum. You should submit a new ticket http://support.advancedcustomfields.com/new-ticket/ or send an email to [email protected]. What I do know is that you can distribute ACF Pro in a premium plugin, it cannot be publicly accessible, and I do know that you cannot distribute your license key with it. Basically it would be your responsibility to update ACF and put updates of your theme to your users.
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