Just to see what would happen, I booted from a cloned external backup drive and installed Catalina there. I did not like the result, so I reformatted that drive and went back to Mojave 10.14.6
What I did not like was that the Catalina installation partitioned its drive. I expect to try it again and experiment with it some more, anticipating the day when I will be forced to move to Catalina.
(I agree that diapers and politicians should be changed often.)