I now have the Pi Zero W controlling X10 via the CM15 connected to it with HomeGenie-beta_1.1.r526
There is some tweaking to do but it does work.
This is using the full raspbian-stretch OS however the GUI is not loaded.
I believe that would be to taxing for the Zero W.
I'm glad to hear you got the CM15 working x10 HomeGenie. Did you end up using a GPIO header for USB. It would be interesting if you had a CM11 and connected directly to serial on the GPIO pins.
You'll be impressed with the scripting and scenes ability of X10 in Homegenie. There's quite a few pre written programs for X10 use on the old homegenie forum too that you might get use for.
Plenty of exploring to be done this weekend by the looks of it. When you've completed your experimenting you can show all the AHP users there is another way to do things.
Maybe Authinx should look long and hard at what you have discovered and maybe they might want to rethink the direction they should take their R&D in.
I've moved on from Homegenie a while back. You're next target should be Domoticz now that the Raspberry Pi/Linux has truly bitten.
Ps I've 15 Raspberry PI's on hand ranging from the original model up to the Raspberry Pi 3. The older ones have been assigned camera duties via MotionEyeOS. Motion detection and notification and working on facial recognition which is very interesting.