Tim:
I can't remember if there's a "practice only" kind of option.
Joe Zeff:
Instead of using dnf -y use dnf -n.
Doing a no instead of yes just abandons the download and install, the kind of thing I'd already described. I was thinking of whether there was an option that went through the *whole* procedure, but without actually doing it. Not that you need to do that, but some things have that feature.