Project Update naming_series cannot be used

Is there a reason that the naming series for Project Update is a data field instead of select?

This seems to prevent using the naming series as the naming rule for project updates. It also prevents updating the naming series under naming settings.

If you try to do either you get:

Series is an invalid Data field.

Only Options allowed for Data field are:

  • Email
  • Name
  • Phone
  • URL
  • Barcode