I filed an issue on the GitHub page but it was almost immediately removed with the author stating that they do not provide support for custom hardware configurations. Although I have managed to figure out the issue on my own.
For future reference the issue was caused by platformio incorrectly assuming the esp32 chip has 8MB of flash when it only had 4MB so all i had to do was add the following lines to the platformio.ini file:
board_build.flash_size = 4MB
board_upload.flash_size = 4MB