Apple's very strict: you can reference frameworks in /System/Library/Frameworks and in your own app. That's all fine, but there's another unexpected obstacle. App can be self-contained (the library executable paths patched using install_name_tool) but the install path still references /Library/Frameworks. See "otool -L"; the first reference is a self-reference, and it looks like you can't easily update it after the library is built. (Or I didn't look hard enough). And yup, leaving that an absolute path referencing into /Library/Frameworks, that's enough for rejection.
Untested theory is that updating "Dynamic Library Install Name" (LC_ID_DYLIB) is enough to fix this. I've set it to:
in place of