Ergodox variant similar to ErgoDash. More popular it seems

Condensed ergo split keyboard. very attractive. Pro-micro-based, good candidate for NRF52840 replacement.

QMK Keyboard firmware fork for NRF52 family MCUs

List of small NRF52840 boards, with USB, lipo charging features and smallest possible size. Compared with NRFMicro

Tiny well-featured NRF52840 dev board with lipo charging and USB-C. Not currently for sale anywhere but doable to manufacture. Arduino Pro Micro pinout compatible, intended for keyboards.