Version 16 is out, with parametric part numbering. Here’s how it works:
The featurescript makes use of an Array parameter, which allows you to specify the individual elements you’re adding to your part number format. There are a few options, along with a “Custom” option, but those are more for clarity than anything else(more on that in a bit). You can add as many parameters as you want, and add a suffix to each (like “-”).

In addition, you can choose to place your actual part number in between other elements, by adding a “Part Number” parameter, in which case the value field isn’t used, and is replaced by the individual number of each part.

If you don’t add the part number as an identifier, it’ll just be tacked on to the end of each part.
There are also a few options at the bottom, including the option to format single-digit part numbers as 2-digit (i.e. “01” instead of “1”), the option to start at an arbitrary part number, and the option to name your parts alongside numbering them.