I've also been trying to duplicate Cremont but haven't used those Geo strains. Looking at the Hanson fact sheet, the CE appears to have the stronger yeasty tendency.
My most recent attempt was with Geo 15, no PC. Result was a slightly wrinkled rind, nice paste but truly terrible flavor- bitter and just off. Not sure what went wrong.
If you do have some success with this please let us know. That family of cheese is kind of my holy grail.