Ebony is usually one of the toughest finger board materials you can get and may stand up to round wounds where rosewood probably wouldn't.
I modified a cheapo fretted bass to fretless and sealed the rosewood board with CA glue which is pretty much a better grade super glue. What a pain that stuff is to work with and will never go there again. Would have been better off using a lacquer or Tru Oil as i paid plenty for a set of D'addario Chrome flat wounds which don't leave any marks on the board from playing and reckon not overly aggressive use of rounds would be ok too.
The fretting of a note shouldn't require much downward pressure however doing bends and vibrato will drag the strings in an abrasive manner that could do a slight amount of damage.
I would initially try rounds on the untreated ebony and see how it goes. You can always lightly sand if marks start to appear.
Cheers, Waz

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