For the voxels I used MagicaVoxel, its free and surprisingly capable of creating things FAR FAR more advanced than what I built. That was the first time I had ever used it, and at first it was just so that I could get the spacing on the beds accurate in proportion because I know how to make repeating objects of the same size, but getting the beds and the gap between them right was driving me insane haha. I think voxels can definitely be a relatively quick and easy way to get a basic 3d model to paint on top of, and its probably less time consuming than Blender, but also a lot less capable. If you want to see some insane Voxel work check out Madmaraca on Instagram, her work is ridiculously cool. Oh, and ImagineFX is amazing, I have all the issues from the last few years haha.