Open5DGUI version 1.1
A little late, but this GUI now fully supports Shad Amethyst's Notation, and should be able to load any game you throw at it. Note that if you use the header "variant" or "board" and input a standard variant, such as just brawns, that will not work as I have not indexed all of the variants. for that case you must input the fen (ie. for just brawns wwwwk/5/5/5/KWWWW:0:1:w).
I also fixed a few bugs and slightly improved the GUI, now the multiverse grid is infinite.