As ChuckPa stated… the repository is using the public releases – that’s perfectly available for Plex Pass users too. The beta updates however are not available as a repo.
There’s already an existing feature suggestion discussing to have such a beta repo too. I suggest you comment/vote in that thread in order to help us avoid distracting or cannibalizing votes.
Unless I’m missing some unique aspect of your suggestion I’ll close it as a duplicate.
