* Previous version of multiple overrides of the default value of ZMK_USB were problematic. Move to using board _defconfig files for the defaults for those, along with proper `depends on` for ZMK_USB that accounts for split and split roles.
* BDN9 Rev2 requires direct polling, interrupts don't work as expected.
See: https://github.com/zephyrproject-rtos/zephyr/issues/28999 PR: https://github.com/zmkfirmware/zmk/pull/736
* Onboard stm32f072. * 3 possible encoder positions. * Underglow/per-key not yet support.
