I am not sure if this of one of those deep, technically tricky questions and I'll make an ass of myself answering it.
I do not see the shutter on my ME Super as being stepless. When in Auto mode it is 'Aperture Preferred' and the choices offered for shutter speed in the viewfinder are specific and defined. When operating properly with fresh batteries the green LED lights up beside the appropriate shutter speed number in the view finder based on the aperture you have the chosen. What the hell the camera actually shoots at is, I am guessing, is your specific question - right? Are you asking that even though it says it is shooting at 1/250th in actuality it may be selecting a different value, say 1/239th of a second?
This is too deep for my tiny brain at 3:34 AM.