If someone told you, or you read somewhere that incident metering doesn't work for portraits or close-ups, they didn't know what they were talking about.

Hold the meter at the subject's position (or in lighting identical to that of the subject) with the dome pointed toward the camera position, and you should get an excellent exposure.

In all the commercial and advertizing studios I worked in (about a dozen), this is the way metering was done for table top, portrait, and group photography. Checks were done on Polaroid before shooting film.

Lee