Well, there IS a way to represent odd meters in Step Sequencer. It's just not 'pure'.
What I do is I use a meter base of 1/4 note, because that is all you CAN do in SS.
SO, to enter a clip of lets say 2 measures 7/8, I create the clip to be 14 beats, but since the meter base is a quarter note, it would play back half as fast as it should. So, I simply insert a tempo change for that clip's duration only, to double the tempo, which then plays the clip back twice as fast.
The end result of the above is that it plays back as 2 measures of 7/8, even though it was initially entered as 2 measures of 7/4. Doubling the tempo makes it play back to sound like 7/8.
I don't LIKE it the above way, but is does allow me to use SS for my odd-meters.
Bob Bone