This is the last WIP I'll upload before I complete the run. This run syncs fully for me on Bizhawk 2.5. The SHA-1 hash of the firmware file I used BEFORE the user data is blanked out is:
Once Bizhawk blanks out the user data (it converts 0x3FE00 and beyond to 0xFF), it becomes the accepted firmware file and earns the green check mark. You can actually produce the accepted firmware file yourself by duplicating this process in a hex editor.