So, as a preamble: with a (very basic) working prototype I’m convinced that the V2 controllers are an amazing platform for, among other things, grid-like step sequencers. (I gather that @mike and @scanner_darkly are also working on similar projects, and I hope they’re having as much fun as I am!)
Thinking heavily about this application, and looking at existing hardware interfaces, I wonder if you’d ever consider making a Medium+ controller that was 9x6 instead of 8x6, essentially allowing an x16 grid with two additional buttons per track (for selection, solo/mute setting and display, etc.). A basic design would be:
Those one-square spots don’t look great, but I wonder if you might be working on one-square controls (even if feedback-only?)
@mike’s Hachi affords this (on both sides) using a large controller, and the Polyend Seq, WMD Metron, and Synthstrom Deluge all use this pattern (Seq and Metron with 1 row of track-associated buttons, Deluge with 2).
There’s probably less of an argument for a Large+ because a 24-note grid would be pretty odd (at least in Western music, unless you wanted to innovate the electrowaltz genre).
And that (plus the Polyend Seq) brings me to my other request: a long controller, 16x6, to allow an x32 grid. This would be around 60cm (which is what the Seq is, with smaller buttons plus other controls), which sounds crazy, but it’s about what a 37-key MIDI keyboard would run.
17x6 would be nice, for the reason above, but unless there’s a way to bump the digital limit up, that wouldn’t matter…
These may be niche enough needs that they shouldn’t be standardized, in which case I might just be asking if you’d consider doing custom controller sizes (for additional $$$, obviously, since the economies of scale are less).