AZ flag is pretty soft, and (I believe) a SWCG will have an accelerated effect on it. Mine is worst where ingress/egress occurs, but pretty much okay everywhere else. I haven't had a SWCG on this pool for about 3 years now.
I can honestly say that all stone will flake, to some point, at some time. Flagstone is the softest I've seen though, and will flake/get "mushy" the fastest. If you like it, like I do, then you just have to deal with the stones as they degrade. Once mine get too bad (and my pool is 8+ years old now) I'll just cut new stones and replace.