I was waiting to post, but since it has already been illustrated, hopefully you will take this in the spirit in which it is given, however bluntly it is put
Simply stated -- you're going about it all wrong
The discussion has been about things like layers etc.
That's a problem.
The smarter you make the device the worse off you are.
Say someone wants a new layout -- does that mean firmware burn ? -- can it even be done at all ?
CSI is built to handle all those layer, etc. tasks in software, leave it to CSI -- that way many people can share the same hardware blocks (economy of scale on hardware purchase), whilst retaining full customizability.
As far a specs, from my experimentation of late:
Colour displays -- Novation Launchpad Mini mk3 has button addressable RGB -- you can use that for simply on/off colours, or multi colour cycling, etc. -- I'll be posting a video after I get the re-arch out.
Display for everything -- C4 is the closest I've seen with:
2 rows of scribble strips
1 encoder
1 pushtop
This way there is no "silk screening" -- cost reduction to help offset the oled cost.
Make sure the encoders are high quality, smooth, and put out at least 10 bit resolution (1024 steps).
RGB (0-255, 0-255, 0-255) colour oled displays would be the Gold plated solution, man you could do real nice track colouring, context indication, etc.
If you are going Midi, will have to do SysEx for text, but that's not bad.
So, in summary, make the firmware as simple as possible, no layers or anything else.
CSI takes care of that.
The firmware becomes much simpler, there is only one layer, etc.
The key is to identify each control, once only, that's all you need, let CSI do the switching.
Make sure you overspend on the displays incorporating as much colour as possible -- look at the Avid S6 to get some ideas as to how powerful colour can be
Litle or no labeling on the panel -- the displays tell you what the control is/does -- it's all completely fluid and undefined, until you hook up software.
For the reasons stated above, the Mackie C4, although from a much larger format earlier time, is still in high demand.
Speaking of being up to date:
Artist Mix / Console One size or smaller is about right for today's on-the-go rig.
You are well within that -- matter of fact, I might up the size a bit -- seems like it might be cramped to operate.
Anyway, just my 2c worth