My hobbies now shifted from gamedev to 3d printing and I must say Asset Forge can somewhat be used for making 3D printed models. 

However, you can't just export the whole obj file of your custom model because the final .obj model isnt optimized for 3D printing. (The individual blocks, by itself, are 3D printable)

What you can do if you want to 3d print your model, dissassemble it on AssetForge, export the dissassembled parts as a single obj file and export it to TinkerCad.

Separate the parts in TinkerCad (that's another story) and reassemble it there.

Export it as .stl file, slice it on your slicer and print it !!

Here is a 3D printed spaceship made in AssetForge

Hey this is pretty cool :)