The F3 series includes support for "analog peripherals," so maybe they decided on that line so they could support the speaker? If that's correct, then that's a

The F3 series includes support for "analog peripherals," so maybe they decided on that line so they could support the speaker? If that's correct, then that's a pretty niche feature for them to focus on. There are forks of qmk and the pro-micro that support the nRF52, but as far as I can tell nothing has been merged into the main qmk yet.