I tried doing both an update scan as well as a full collection rescan, and neither will remove the excluded items from an existing collection. I then tried backing up my strawberry config and database and starting from scratch, and can confirm that it does prevent the scanner from adding the excluded files.
So asking once more, is there a good/easy way to remove files from an existing collection that should've been excluded? I even looked at the database to see if I could delete directly in there, but reluctant to do that because I don't know what kind of references may be in the database that would break if I just delete a bunch of stuff from the songs table.
Not the end of the world if I have to start over, just want to confirm whether there's a better way before going that route. Thanks again.