apparmor_parser doesn't use the .features file from the --cache-loc directory
man 8 apparmor_paser
says that when using --cache-loc, it would implicitly use the .features file from the provided directory:
-M n, --features-file n Use the features file located at path "n" (default is /etc/apparmor.d/cache/.features). If the --cache-loc option is present, the ".features" file in the specified cache directory is used.
However it doesn't work like that and one has to explicitly provide --feature-file.