Thanks for this important info! Looks like I'll be staying on Catalina for the foreseeable future and maybe longer! Perhaps the replacement for Big Sur will include a fix for this problem.
Who is in charge of basic details like this?! Should I blame myself for buying an iMac with
only 500GB of storage? I do keep an eye on "free" space and offload most data and many apps to eternal drives. But Apple is making no incentives for folks to buy more local storage. Apparently, the installer folks assume everyone has so much memory that checking is not needed?!