TL;DR
Adding resources in a mod generally requires adding an autoplacer. This could be simplified with optional parameters to AutoplaceControl.
What?
An AutoplaceControl is always going to need to be associated with some planet, whether additional or not. Having a "planets" parameter in the control to handle the registration of the control with the planet_map_gen would simplify adding new types of resources significantly. Something like a planets = {} array parameter that can be empty as well, to keep the current behavior.
Why?
Currently it is necessary to add an AutoplaceControl, then add the control to the planet_map_gen.autoplace_controls, as well as adding the entity to autoplace_settings["entity"].settings. This is complex, and adding an autoplace for anything is going to need to go somewhere.
[2.0 API] Autoplace Settings
Re: [2.0 API] Autoplace Settings
[Koub] Moved to Modding interface requests
Koub - Please consider English is not my native language.