Interesting, during my dive down the rabbit hole trying to understand things and collect info, I read somewhere that arcs are not supported, but yes I can now see that they are thanks.
I can see Fusion has several Fanuc post processors: Fanuc compact, with G91, inspection, or turning. I'll look into these.
It's likely the generic Denford post processor will do the job fine but I don't have the experience to decide.
What software do you use?