I just installed Catalina 1015.4 Beta 5. All went well and all my main workflow Apps seem to work just fine. I am sure there are fixes in this Beta. I do not know of any new features, but we will see. It has only been a few days since the last Beta, I think we are getting close to a final release of 10.15.4 for Catalina. Apple also released the usual Beta updates for their other operating systems.