Oh I totally agree with you on that, Shooter. Definitely the right way to tumble in my opinion as well. It's not clear if the OP (unless I missed it) just sized or also trimmed and chamfered, thus resulting in his original post's issue.
Having said that, with no chamfer, the case mouth will still get banged up enough to be considered "peening" when run with too much brass or run too long. I've measured just to confirm what I can see. Granted, it's not something crazy, but it seems to be enough to increase the resistance felt by bullet seating. Just my observations. Oh well. I've really got nothing more to add to this thread so I will leave it there.
Good shooting, sir.