I'm going to go out on a limb and state that, in all likelihood, a material that is not compatible with an epoxy substrate is one that is best avoided.
For me, a topcoat that explicitly states it is not compatible with epoxy makes about as much sense as a primer that is not compatible with body filler.
I now utilize epoxy primer extensively on all my top-shelf work , as its attributes are many, and shortcomings few. I have yet to have a problem, in over five years of extensive epoxy primer use, that can be directly attributed to its proper application.
Just my 2 cents.