Infinite Undiscovery Save Edit (or XeAlgorithm) wanted

I’ve gone through dead end after dead end looking for something that will help me modify my saves for Infinite Undiscovery.

I’ve got Horizon and Modio running, but the trouble with this game is that it uses a custom checksum to validate the saves.
I’ve looked all over for a working copy of XeAlgo or XeAlgorithm, but to no avail.

Does anyone know how to get past that checksum? Or at least knows what custom checksum data I should use with HxD’s tools?

I spent the weekend trying to riddle this out, but I need help.