I can't tell you about what else has changed other than in my experience with the Witness software. I have started with v1.26.6 and went up to 1.27.11. The 1.28.0 and 1.28.3 that I am running now had significant performance improvements. It used to take me 30+ minutes to re-start the Witness node and now takes less than 5 minutes on exactly the same hardware. It also takes less memory and seems in general to put less load on the system.

So the code is definitely improving and they are making it easier and easier to install and run the witness nodes. Software really is improving. What Hive needs is major marketing dollars to place it where people are and I guess that takes millions of dollars...