Be careful.

If you expose the surface to air, put mix a 1:3 solution of muriatic acid (1/4 cup acid to 3/4 cup water) and then put a spoonful on the 'scale'. If it's calcium scale, it will fizz. I don't have any experience with FG pool surface problems, but right now, my guess would be manufacturer defect, not scale.

Once you grind, you've taken responsibility for it though. So, I'd hold off. You can still swim and NOT affect any warranty or mfg defect claim. Waterbear is out of touch at the moment, but he has some knowledge of FG pools. You might want to wait till he's back.

Also, I'd call the mfg back and ask "What sort of scale?"

I'll get your pics posted, but I don't think they will necessarily be that helpful, till we get someone who has some experience with FG.