having grown up in stl and now in kc for the last 20yrs, i'm a 4th generation fish guy. i know the missouri area ozark country like the back of my hand.
i've used tons of different limestone from the area in my fresh and turtle tanks. mostly slate-looking pieces for shelf building.
my ph raises everytime i use a dry piece. if i pick it up from a canoeing trip from underwater it doesn't. but then you are facing parasites.
i believe texas holey rock to be a lot different than our area.
i haven't used any of my pieces for salt, but i thought i'd throw out my experience. it's really kickbutt cheap stuff for a planted cichlid tank once it's cured.