I got FusionPBX Provisioning to work on my beta HomePBX system. Turns out that you must specify only one of TFTP or FTP provisioning directory, or else the system will not be able to write out all of the files. This is because it unsets one of the variables ($file_name) after writing out the file once, but will still try to write out the file a second time in the FTP directory anyways (with an empty filename). Fun times. Because the system writes out all of the files to this directory, I was able to cobble together an nginx config that allows my Polycom phone to provision and push logs to the provisioning directory. Still no luck getting it to register though.