Hi there, this is Joey from the App-Bridge team.
I am sorry for the radio silence on our end. Although we are very excited about the benefits of the Unframed mode, we are not accepting new beta testers at the moment.
Thank you for reaching out and bringing up this issue. I am currently removing the out-dated page from our docs website to avoid any further miscommunication. We will follow up in the near future, as soon as we are ready to onboard new beta testers.