Disc brake rotor w/beveled nose (= Unicorns?)

Easy peasy. Chuck it up backwards on a brake lathe. Mount the drum brake arbor on the machine, but flip it around backwards so the bit points toward the work. You'll have to work both cranks to manipulate a bevel, but it will be cleaner than a grinder. I've done it a few times just for the reason you describe. To clear center caps. It doesn't take much to get it done.