A little more complicated, but a lot more versatile. I had a similar issue, where I wanted a large amount of extra keys for macros/hotkeys. I bought a planck k

A little more complicated, but a lot more versatile. I had a similar issue, where I wanted a large amount of extra keys for macros/hotkeys. I bought a planck kit from olkb (https://olkb.com/planck/ https://olkb.com/planck/) (which is just one of many keyboard kits that will run the QMK firmware (https://github.com/qmk/qmk_firmware) https://github.com/qmk/qmk_firmware)) built it and rewrote the keymap to output my special keys. Later I went on to wire up a couple simple industrial style footswitches to a cheapo arduino pro micro clone and put qmk on there. A few other interesting and smaller keyboard kits can be found from vendors like https://www.1upkeyboards.com/ https://www.1upkeyboards.com/ (the sweet16 macropad/keypad) and https://keeb.io https://keeb.io (the chocopad or just half of any of their "ortholinear" split keyboard pcbs.