Hi Apex community,
If you’ve been having compatibility problems with W3 Total Cache and other speed optimisation plugins I’ve discovered a neat little fix to disable the plugins only when using the Cornerstone Page Builder. This uses the Plugin Organizer to create a custom filter.
Full instructions to make X theme compatible with W3 Total Cache can be found here - How to make X theme & Cornerstone compatible with W3 Total Cache
I’ve tested with X theme and Pro, and with old and new installations. I hope it helps. Let me know how you go with it. 
Cheers,
Bernard