When I first tried this new patching system I had problems with the error: patch_group should not be a comment.
I was using the patches as published by GeoffR which in some cases have the commented line "# patch_group = "
After removing the comment marker (#), from these "patch_group=" lines, the patch progressed ok.
Bit of a pain going through the patches and editing the problem lines rather spoils using the nice kobopatch.yaml feature. I assume this is a temporary glich.
Once the files had been patched I compared them with those from the original patcher and they where reported as being identical.