GalaxyForge, Steam, and DLC

Hello,

I've recently installed Sins: Rebellion on Steam, and I have the forbidden worlds and stellar phenomena DLC.

I have been trying to make custom maps using GalaxyForge, but I can't seem to add any DLC content For example, I can't add oceanic planets. My GalaxyScenarioDef file doesn't seem to include any of the extra planets either. Additionally, my icons folder doesn't show these planets.

I can't use the in-game map designer for my intended creation because it doesn't allow me to set start positions or exact planet locations (restated, I can't create a non-random map).

Is there something I'm missing or need to re-download? Or is DLC content just not available in GalaxyForge?

Thanks!