So to be honest I don't think they stack well since you'll run out of headroom too soon and it becomes a noisy square wave. I'm leaning more towards a dual channel thing or a simplified high gain distortion circuit stacked with a lower gain overdrive circuit. Either way, besides you lot there's not a whole ton of requests so its never been high on the to-do list.
But maybe I can pull off a small batch of something soon.
For the record - I'm not in the camp of pushing for a dual MBD. I'm just willing to buy (read: have bought) pretty much all of your creations to try them. Of those, I hung on to an MBD-2 for each board and a mammoth tamer, because it fvcking slams with fuzz pedals. So if it's between shifting gears to the dual or finishing a rad fuzz - I vote rad fuzz.