I was going to mention this simply as a warning - abalone shells have, in the past, caused problems with plaster discoloration, specifically brown rings forming around the shell chips. The culprit seems to be non-pool grade shells being used that were not properly processed to remove all of the organics in them. These organics then slowly leach out into the plaster, react with chlorine in the pool water and form a brown ring. Nothing can remove the stain and the fix is often to simply chip-out and redo the plaster. I feel better knowing that this product appears to come from CL Industries so I am hopeful that they have good quality control procedures in place. I believe in all the cases where brown mottling occurred, the abalone shell came from an unspecified source.
I'm mentioning this only as a warning and something to keep an eye on. You might even discuss it with your PB (hopefully "on the record" so you have a paper trail). That way, no one can say this is your fault. If you look up "abalone" and "brown stains" on this forum, you'll find several posts about it. I think there were also articles written in the usual pool trade magazines about it as well, so it's not like it's an unknown problem.