ok never mind i found my mistake. the file extension was wrong. i had ".BIN" and it has to be ".bin" then the .sbi file will work correctly.

@sgtjimmyrustles
Already have a backup that I update regularly and it seems to be the best thing to do.

In case sd gets corrupted, just write the image and done..

@ramospa I have NO idea how I originally missed this post, but just wanted to update this to reflect that these instructions worked perfectly for me. It seems that after all this time, the cheats found on the Reddit thread in the OP were the right one, they just had to be entered in a format familiar to Retroarch. I found it easier to store the cheat file in /home/pi/RetroPie/cheats, but otherwise, 10/10, BRB playing this game at last!