I'm not too sure if it's do-able, but I have a 436-PT (Australia) version. For whatever reason, there is an apparent lack of firmware updates for this version of scanner in our region.
I was able to download firmware 1.25.0 and load it onto the microSD card. From there, I changed the filename from 'BCD436HP_V1_25_00.bin' to 'UBCD436-PT_V1_25_00.bin. After disconnecting the scanner from the PC, the Scanner had recognized the firmware, but failed due to update due to a 'checksum' error. No surprises there, I guess.
Whilst a little sly on my behalf, is there a magical way to get around the checksum error and trial out this new firmware?