Did yours ever sort itself out?
I finally gave it a try. Used Aurora store to download the old APK, put the Verizon ACL in, RCS connected and I updated to the current beta. RCS has remained connected for a week or so now.
I did attempt to toggle it off then on, and it would not reconnect so I had to go through the whole process again.
A word of warning for those of you who like to keep a clean inbox, switching to the old APK unarchives everything. You will have to manually archive everything again. 😮💨