Don't need "custom" in-line hardware. Just get this. https://www.1upkeyboards.com/shop/controllers/usb-to-usb-con...
Re:4x4 Macro Pad Kit
by mcpeepants on Wednesday October 07, 2020 @02:15AM
(#24705737)
> What I would love however is an inline monitor to see what keycodes I'm issuing.
this is actually very simple to do with QMK if you have a board with an OLED display. it's also implemented in the default keymap for a bunch of the split ergo boards (Lily58 is one that has it)
I have thought about custom in-line hardware but that's honestly as complicated as QMK. Plus latency.
What I would love however is an inline monitor to see what keycodes I'm issuing. It gets...zany.