What makes a good micro porous glass plate for the bed

My setup is three R2's and one clone R2. I use micro porous glass plates mounted on a flexplate system onto which I spray aqua net hairspray.

All glass plates fail eventually and the thermal cycling makes glass shards come off the plate. Since I use a 5x5 auto leveling grid and only print on 1/4 of the plate I am able to rotate the plate to extend it's life. I get about 200 identical prints before failure.

Some plates have a great deal of adhesion and some do not work well, allowing curling at the edges. I have found that the printed grid on glass makes the difference. If the grid lines leave a hole that is larger than the thickness of the printed lines I will get curling. The thicker the lines the better. When the printed lines are double the thickness of the hole I can print even the smallest parts on the plate.