If I hold my DeWalt ROS with a fresh disc of Norton 60 git in one spot, I will be down to wood in about 1 minute. Over the years I swear by Norton disc. I reciently was using some bosch discs fairing epoxy on my most rercient boat and they can't come close to the longevity of the Norton discs. I've also use 3M & Sungold. I haven't tried the new (green) 3Ms yet. Home depot and most woodworker stores carry Norton.

However I don't think any disc is going to make the difference that you site. 8 hours of sanding to strip a deck - which usually has one coat of glass and a ftwo fill coats of epoxy? Maybe I underestimated because I've never done it but I wish you were local because I'd love to give it a try. I have accidentally sanded into glass before and it seems to happen pretty easily and that's with 220 grit.

When I sand epoxy/glass, I position a box fan blowing the dust away from me. It makes an enormous difference - and outside if possible.

Good luck with it.