I have been told that maple fingerboards need to be coated. All of the ones that I have seen have been. The issue regarding maple fingerboards for fretless, as I understand it, is simply regarding maintenance. With an uncoated rosewood or ebony board, when it is eventually time to sand it, it is a relatively simple process. With the coated maple, the coating will be sanded off and will need to be reapplied.
As far as sound goes, the maple boards that I have played have been pretty bright (IMO a bit brighter than ebony).
As far as sound goes, the maple boards that I have played have been pretty bright (IMO a bit brighter than ebony).