Great keyboard and a fun build!
Modified the base STL to support tenting, mini-USB for the interconnect, and a hole for microswitch for reset needed when uploading new firmware. Script to make the modified base at: https://github.com/Lenbok/scad-redox-case
The bolt heads are slippery on the desk - my plan is to improve grip (and also make the levelling a little more tolerant of getting the lengths exactly right) by either molding oogo around the heads, or failing that locate some plasti-dip to dip the heads in.
Used right-angle headers on the arduino to allow low profile but still removable (actually soldered the headers with the long side through the arduino, then clipped the legs and slid the plastic off the short side of the headers to make them even lower profile).
As with fumbucker's build, used I2C and EE_HANDS. Currently using a layout based off his one at: https://github.com/xia0/qmk_firmware/tree/master/keyboards/viterbi/keymaps/xiao but choosing a keymap is going to be a learning experience since this is my first ergo style keyboard.