There is definitely one good thing about OS 10.15.6. If folks remember, OS 10.15.5 "broke" both SuperDuper! (SD) and Carbon Copy Cloner (CCC) regarding bootable backups. CCC issued an initial fix almost immediately, then came out with another version a week or so later. SD meanwhile still had (nor has) no fix. Well, I queried Shirt Pocket Support earlier today about a status, and I was told that OS 10.15.6 fixes the issue that came up via OS 10.15.5. So, one (including myself) can use the latest version of SD after installing/upgrading to OS 10.15.6. That is certainly good news, as I want to remain up to date. And especially where OS 10.15.6 will, likely, be the last version of Catalina Apple releases.
I will make one final SD backup for each of my Macs on Saturday, do a fresh. clean installation of OS 10.15.6, and then migrate/copy needed files, folders, settings, etc. from that just completed backup. I will then be good to go.