Availability of public publishable URLs for beta-testers

Description
We are currently developing an app that we intend to submit to the Zoom marketplace. However, we want to run a closed beta with a set of users before the submission.

I understand that this is possible through publishable URLs. However, publishable URLs have recently been disabled, as per the documentation and this post by @will.zoom:

When will publishable URLs be available again? We will go through the standard marketplace approval process but it’s important for us to have the beta testing process in place before that. Unavailability of this feature has also affected our customer-facing timelines. It will be great to get some clarity around this.