Since this project is by a single person, I do not have the capacity to create services (service directories, source directories) for every package. For this reason, I try to create at least one service for each category or kind of package (e.g. webserver, display manager, etc.), to make it easy to copy and adapt those.
Which services I add will ultimately depend on what I use myself. I highly encourage you to create your own service and source directories.
That said, if you can not find any package similar enough to your needs to copy and adapt, feel free to ask on the goetia mailing list.