* I find the USB Type C to the host to be unnecessary. The USB HID protocol would use only four wires anyway and a USB Type C cable is a quite thick cable.
That is, unless you also put a USB hub on the keyboard or something similar that would take advantage of the extra capacity.
Some people have used USB Type C only to gain a reversible connector - but that is unnecessary now that reversible USB Micro B plugs exist.
* I don't think placing the connectors and screen on the inside is a good idea. That would make it difficult to place the keyboards close together. People who put them closer often angle them more which would move the connectors even closer.
* I would like that the new ErgoDox should try to regain some things that the Infinity ErgoDox did not carry over from the original PCB layout.
-
1u keys at outer columns (already mentioned).
-
PCB-mounted stabilisers (already mentioned)
-
1×1 keys in place of 1×2u keys in thumb clusters. (more like Maltron than Kinesis ...)
-
Compatibility with existing ErgoDox cases (possibly)
There are several cases out there that are compatible with the original ErgoDox but not the Infinity.
The Infinity ErgoDox has (to my knowledge) always been sold with a case, however, where as the original is available in kit form. Cases for the original ErgoDox exist in wood, PVC, metal and acrylic, with or without a a plate.
However, there is one way in which not having any border above the numeric row would be a win: you would be able to get negative tilt without lifting the keyboard as high.
Suggestions for further improvements:
Break-away thumb section:
The ErgoDox has been criticised a lot for the thumb keys being too far away for many people. This has resulted in many builders modding their keyboards in various ways, and I think is also the reason for the ErgoDox-like clone
Diverge 3. (Which BTW also has bigger offsets between columns, which could also be argued to be more ergonomic.)
The Kinesis and Maltron work better because their thumb sections are not in the same plane as the finger keys.
One mod I have seen broke away the thumb section and reconnected it with wires. My suggestion to you is that you redesign the thumb-section so that it can be easily broken away from the rest of the PCB and reconnected with a standard ribbon cable. That would make it easier to perform this mod.
That could also permit replacement PCBs for the thumb section, with for instance a thumbstick that would be easily accessible.
Do note that there exist several footprints for thumbsticks of that size. There are also smaller types of thumbsticks available but not all of them are known to be very durable.
BTW. Another type of input device I have thought of would be a roller in front of the keys, similar to a Rollermouse but fixed horizontally. However, I have not found that as a discrete component: I think they are custom-made for the keyboards that have them.
Indicator LEDs facing inwardsThe original ErgoDox has three LEDs for layers/Scroll Lock/Num Lock/Caps Lock on the keys in the innermost column, but they are facing outwards in the original design and only the LEDs on the right side work. Your backlit keys have them facing outwards, which is good.
The ErgoDox clone ErgoDone did it even better: It has
separate LEDs facing inwards.
Those LEDs would therefore not be part of the backlighting.
1×1 and 1×2 inner columnAs an alternative to the two 1.5u keys used for the inner columns, allow a 1×1 and a 1×2 key. Those would be easier to source.