(TECH) Upgrading/Flashing RePhone GPS/NFC modules firmware

I am going to do the flashing as described at the top of this post, but after looking at the code (and the generated file from the python script), there’s something I need explained to me. The hexfile from the gps code fix only contains gps code, yet the firmware is being erased and reflashed with no offsets that I can find. How does the flashing routine only update the part of the code which is gps-specific? There are address offsets in the hexfile starting at 0x1000 however those are the same offsets for the NFC hexfile - and those offsets are discarded when the code is generated by the python script.