I have one 32-bit app that I still want functional, so I made a clone of my Mojave system prior to upgrading to Catalina. I'm keeping that clone viable until I know that I don't need the app anymore. I also have two Catalina clones plus Time Machine, so I'm completely backed up. My experience with Catalina has been similar to Joe's; no problems.

You could consider something similar with your Sierra installation.


Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P700, Photoshop CC, Lightroom CC, MS Office 365