I got an Adafruit Grand Central M4 Express SAMD51P20A. Unfortunately Adafruit seems to have put all their eggs in the "CircuitPython" basket, it has a UF2 bootloader and I find their docs are jumbled and I got lost to use C with this MCU. I did not see any M4 listed in the Boards Manager.
"The bootloader is also BOSSA compatible, so it can be used with the Arduino IDE which expects a BOSSA bootloader on ATSAMD-based boards"
So I have to go to the command-line with this and a few more hoops to jump through to get the .bin to work?
What is the best way to get running with the SAMD51? Or should I go with a SAMD21, it seems to have some support.