@adafruit's Feather boards are great, but sometimes I'm too cheap to leave them in finished projects, so I made a minimal replacement, with practically everything removed. It has literally 5 components, but still runs CircuitPython and has standard pins.
https://hackaday.io/project/171381 

The swiss cheese has arrived.

And here it is with the bootloader and @CircuitPython firmware, in all its cheesy glory.

So I swapped the SCK and MISO pins. Fixed gerbers available at https://hackaday.io/project/171381  or you can swap them how I did:

Version 1.3 arrived — with a USB-C socket made out of PCB. It works, but only with USB-C to USB-A cables, and not with actual USB-C sockets, because I forgot pull-downs on the CC pins. Ouch. Working on version 1.4 now...

Added the required pins and pull-ups (it's getting crowded in there) and, to make use of that empty area, I also added some prototyping holes in there — so the "cheese" holes are now just silkscreen. I will let this sit a bit on my disk, and if I find no issues, order it later.