Solved my ghost xtreme a couple days ago!

The key was realizing that by marking the centers of my Jing's pyraminx (actually pyraminx master, but pretend those extra cuts aren't there), it would be exactly isomorphic to the ghost xtreme. Figuring out algos there wasn't nearly as difficult since it was it's far more visually intuitive.

The thought process was realizing that the marked-center Jing's pyraminx is trivially equivalent to this by just gluing on the extra pieces (the extra cuts on the pyraminx master helped me see this)...

which is trivially equivalent to a marked-center ``2x2 octahedron" (aka a Skewb Diamond)...

which was what I interpreted the Ghost Xtreme as! I didn't have any prior experience with skewbs/pyraminxes and just picked up the master pyraminx not even a week ago so this was a huge realization for me. I knew that the octahedron and cube were dual but never realized that the tetrahedron was so closely related to the pair!