I know the keyboard is already hardware—and that we all have screwdrivers 
I don’t have mine yet, so this is purely idle speculation, but I’m wondering whether it makes sense to consider integrating other controllers with the Model 1. I’m thinking knobs or buttons to further control layers and lights, or extra lights or readouts for status display.
Looking forward to getting my hands on one of these!
I remember reading about extension headers. You can see the PCB here: https://twitter.com/search?f=images&vertical=default&q=keyboardio&src=typd and the expansion port.
If you do something document it! You may be the first
I’ve been thinking for a long time about building a small platform that would let me have a Magic Touchpad between the two halves of the Model 01, but that may be lower tech than what you’re thinking of.
One idea I had was to attach a card reader port to the extension headers and use the embedded num layer as a “secure” pinpad. That would however require me to reimplement the full card reader protocol in firmware…!
(I put “secure” in quotes because it’s firmware, and therefore insecure in principle - even though there are decent protections against flashing malware)
I would love to add capacitive, IR or light sensors to the keyboard’s hand rests. This way the M01 would know, if I have my hands on. This would allow to automatically switch to a dedicated text editing layer that has cut/copy/paste and other needed actions on the left hand side keyboard home row while I operate the mouse with the other hand.