Can I use Time Machine after clean install of Catalina?

Yes, but you said you would be choosing individual files. Inheriting the backup just means that it will preserve your older backups. Then you can go about restoring the files you need.

Still, it's easier from a clone. Just don't reinstall the User Library (~/Library) because that is likely where most of the issue lie.

They may not be, which is why I suggested cloning. You can try if you like but you'll be prompted to "inherit backup" and you should choose to do that.

plutomedia wrote:

I'd like to do a clean install of Catalina, but want to make sure that wiping my HD doesn't lose my connection to my external Time Machine backup. I'd like to pick and choose what to restore after reinstalling the new OS, rather than "restore from backup" the whole thing.

Restore items backed up with Time Machine on Mac - Apple Support

https://support.apple.com/guide/mac-help/restore-files-mh11422/mac

I would suggest making a clone of your present system.  You can use a cloning software like SuperDuper! or CarbonCopy Cloner. The advantage of the clone is that you will be able to drag and drop, as unlike TM it is the same file system as Mac OS.