Restricted Registration

We are currently using the universal login experience. We have a scenario where we dont want open access to the registration but we do want to allow for registration when accessing specific links from our site. Currently this doesn’t seem supported as we can disable the registration link on the sign up page but then when we attempt to bypass the login and go to registration its throws an error: error=invalid_request&error_description=signup%20is%20disabled&state=T2R0bC1GeWcuS0VReXpHMmFkczM1TWg0aUhJYld2QnZDNGd0Ml9iaWEyNg%3D%3D