Yes, I tried to put the bolts in the corners, but was limited with movement due to only so many ways the pier adapter would fit...
I drilled the holes before it was completely cured as much less chance of cracking, in fact when I got near the bottom of the holes when drilling, the dust coming out was still damp, I left covered for two weeks before drilling, but it was back end of last year and was very wet during the two weeks...
If you wait until itโs fully cured before drilling, , much more chance of cracking, also keep the block damp by wetting every day, after the first couple of days, and leaving covered, as it will crack also if dries too quick....and you will need a good SDS drill for the holes.... ๐๐