I know we have access to changing aspects of the features that already exist, but I would like to be able to make our own and have them show up on specific planets... IE: You could make a custom metal spot type for each planet biome and have it actually show up.
I have had a bit of a poke around while seeing if I could generate geothermal spots. As far as I can see you can't make new feature types. I think the best course of action would be to ask Uber and see if they can implement custom feature types the same way they added the custom unit types.
Depends on how much you mean by "custom metal spot type". If it's just the model, you could make a biome type (or shadow them) with a feature of a modified metal spot with a different model, and then set the game metal sliders to no-metal. It limits the metal distribution to the one specified in the biome though.
Yeah, but I'd still like it to be a bit more controlled than that, IE be able to tweak it's values in the system editor. The other option would be to have features have a biome-specific model capability, but custom features would still be good.