@ozsouth I have used your recent 2018-Kernel-kits which have built kernels successfully which also boot!
Tested in F96-CE_4.
One thing really strange is now no matter which RT patches I am using the PREEMPTION selections are NOT showing any full real time options.
I have now tried with kernels I already compiled as RT and the same thing is happening. Yet the RT patches are applied without error!
This is now occurring in the 2018K-Kits and the most recently woof-CE generated kernel-kit.