Well, technically it is basically unstepped. But this is very subtle and I wouldn't count on it.
Here's a photo of the adjustment ring, the Seikosha on the right and the Synchro-Compur from a Rollei on the left-
The area circled in red is where the speed adjustment happens. A pin rides on the inner edge of the opening. As you can see, the edge of the Synchro-Compur has definite steps while the Seikosha is more sloped without obvious steps. Theoretically, this means that the Seikosha is infinitely variable along the two main sections of the path.
In practice, the odds of hitting points with any precision is pretty slim. I wouldn't give it much thought. The one place you might really want this on the Seikosha is in the jump from 1/10 to 1/25, and that happens to be the serious jag in the middle of the opening as it moves from one speed series to another.