Chuck:
That "knight Rider" effect is a chained effect. Master/slave is "Master does this, slaves DO THAT TOO!" or at least that is the regular application. There's really not often a whole lot down the line as far as telling a slave which slave is which. I could be wrong, but there may be a few fixtures that do assign a slave ID to the slave assignment. But really, master/slave communication is the same as DMX from the standing of "it's only going in one direction", so there's no "talking back" between fixtures.
Multiple units require more control. If you want to do the knight rider thing, you're gonna have to know your color and dimming as well as movement. Then repeat the pattern but offset on the next fixture and repeat.
There are SOME fixtures that have speciality controllers to do similar type things. I'm not sure what they use for control, but it could be DMX, or it could be proprietary. I think both ADJ and Chauvet make a tube light set that gets plugged into a special controller, and this controller in turn is sound activated and behaves like a neat viewable 31-band EQ.
If it was me, I'd just do my control in MyDMX. It is what it is for.