Ok I did some further looking today,
I still cannot apply a patch, but I have found that the patcher will quit if the directory the patch is being applied to has a space in:
E.g.
causes instant quit.
Using "%cd%" variable, translating to "E:\Games\Among Us" leads to
Code:
Exception: Patch not in BINARY format
Renaming to E:\Games\Among_Us leads to
Code:
EInOutError: The system cannot find the file specified
All using non Xdelta patch method.