The PBI terminology can be a little confusing at first, so I'll try to clear that up. There are PBI packages, which are all-in-one archives that can be installed on a computer. And there are PBI modules, which are basically instruction sets telling a build server how to make a PBI package. Basically PBI modules tell the build server what pieces it needs to assemble a PBI package which can be downloaded and installed.
The PBImaker program creates modules, the instruction sets the build server needs. You're welcome to submit any modules you make to the PBI developer list where we can look over the module and add it to the PC-BSD build server. It'll create a PBI package that will then be available to all PC-BSD users.
I hope that's clear. The address for the developer list is firstname.lastname@example.org