Default CM11 new theme engine

I noticed recently that CM has released a revamped theme engine. I tried using the theme engine in the recent Mahdi rom but found it very buggy to the extent that I would be greeted with various FC's, occasionally ending with my phone crashing.

Is this a known issue with the new theme engine in that it's buggy and still kind of beta, or more likely a problem Mahdi side?

Thanks.
Bob

LG Nexus 4:: KitKat 4.4.2 stock factory rom, Xposed/Gravity Box
Samsung Tab 2 10.1:: CM10.1 official build rom
HTC One X +:: Insertcoin 4.1 Sense 5 rom (now retired from service!)