In my efforts to configure my Boron LTE-M to use a 3rd-party SIM card, I have managed to end up in a bricked state. I have tried to flash varying versions of bootloader/system-part1/tinker to the device via particle-cli and at some point I must have broken the software state. The device now blinks red and I can fall into DFU mode (flasing yellow) by pressing the mode button for 10+ s.
I really need help to reset the device back to some sort of (working) factory state. Your advice is most welcome.