I'm wondering if anyone is live with v12.5 and is using mail2 that would be able to explain how mail2 works with v12.5. Are there any changes or can we do away with the custom screen and go back to using contact point preferences?
We actually get a lot of value out of the custom screen regardless of contact management since we can use it to see what campaigns a constituent has received, whether the campaign has been clicked or opened, resend the campaign, or just see the email's contents.
But in regards to subscription management, you should definitely get in touch with the mail2 people -- we haven't implemented this yet, but I believe you can use contact point purposes to manage your mail2 list memberships directly through the use of a service interceptor plugin they have developed.
http://mail2support.lynch2.com/customer/en/portal/articles/1662824-tessitura-service-interceptors-for-mail2-functions