smokefree, you've compared the original fw_all.bin and a GarminCure3-ed fw_all.bin. GarminCure3's patch is a bit different from that boot.bin patch.
Looks like the experiment was not 100% clean. Maybe it's a bad flash block which was "frozen" with GarminCure3-ed fw_all.bin piece. Or maybe it's your mistake.
Can you make fw_all.bin full of 0x3E bytes with the size of the dumped 14.bin. Then flash it, then dump it, and compare the flashed one and the dumped one?
It's not dangerous to flash garbage instead of fw_all.bin, you can always flash something else in pre-boot mode after.