Everything I know (limited) about flashing the XD 60 (atmega32u4) with dfu-programmer using the command line.
dfu-programmer --help
See list of commands for dfu-programmer
- Erase existing memory
dfu-programmer atmega32u4 erase --force --debug 1000
- Flash with .hex keymap
dfu-programmer atmega32u4 flash keymap.hex --debug 1000
- Reset
dfu-programmer atmega32u4 reset --debug 1000