Yes, that worked. Thank you very much.
Bottom line, in this case there are two lines that need to be added to the platformio.ini file:
board_build.arduino.ldscript = flash_without_bootloader.ld
board_upload.offset_address = 0x0
Also, tried it with my Adafruit Qt Py, and that uploaded correctly.
Again, thank you very much for looking into this for me.
Jack