Yes, stop with the sanding discussion already. Sanding will remove metal and damage carbon. Sanding will do much more damage to your fork than the normal, minimal amount of oxidation on the fork tips.

"Hey, I have some butter and honey droplets on my mahogany dining room table - would it be best to use a chain saw. or a chisel, to remove it?"

No more talk of sandpaper or of metal brushes.

BTW, the epoxy in CF composite is notoriously hard to attack chemically. Neither diluted vinegar nor CLR will affect it.

Stop worrying about the non-issue on your fork tips. Wipe em off with a damp rag, put your wheel on, and enjoy riding the bike. You're bike (at least the fork tips) are in much better shape than you thought.