Have you checked out 08-PureData/multiplexerCapelet/ ? It should run with heavy and the multiplexer capelet. The capelet needs to be enabled via command line, which I think is -X 8 to get your 64 channels.
So your command line should* look like
./build_pd_heavy.sh /path/yo/your/project -c "-X 8"
where -c "-X 8" passes the command-line argument to the running code.