Adding stuff to the "other" panel

The level builder has a section at the bottom of the creation panel called "Other". It is currently populated with three items... "Scene Object", "Trigger", and "Path".

Is there a way to add a new item to that list without a change level builder code? Ideally this would function similarly to how the project resources system works.

My need to be able to place game specific special objects like spawn points, enemy generators, physical effects, whatever that usually don't have a visual representation but have script class associated to them.

Thanks!