By specular reflections I assume that you are addressing small regions of highlights that exceed the scale of the film, the paper or both.
Originally Posted by noseoil
Typically specular highlights will be relatively small in relation to the more important tonal representations. For that reason I would not concern myself with specular highlights whether that would be with a spot or an incident meter. The reason that I would not concern myself with these is that they would tend to skew the development indicated.
In BTZS metering the meter dome would be pointed toward the camera lens from both the sunlit and shaded positions. The incident reading from any of these positions would be representative of a five stop scene brightness range. If the scene brightness ratio exceeds seven then the development is reduced. If the scene brightness ratio were less then seven then the development is expanded.
If you are speaking of larger areas of reflective nature in which detail is desired then the scale of the materials will not be exceeded if the incident metering is done in the manner that I have described.