We currently have at least 17 babies doing well in the cubes and 3 or 4 more running wild in the tank with Quattro. I've only seen 3 dead babies (all of which climbed the netting and got stranded high-and-dry) so there could be quite a few still hiding in their little shells.
Apparently the mysids spent too many hours in the cold. Sachs was really good about getting a new order expressed to me in an insulated box, and these made it fine, but we had to go almost a week without live foods because of some other issues that caused a delay in me re-ordering.
Fortunately, persistance with the frozen foods paid off! By the time the live mysids arrived, many of the babies were showing definite interest in cyclopeeze and even whole, frozen PE Mysis. The live foods are much more convenient, but the cost gets out of hand so quickly! The live mysids were depleted several days ago and we have been feeding nothing but frozen ever since. Not sure why frozen worked this time... maybe gently dripping them down the side walls of the cubes helped... maybe just having the babies confined. Still a lot of work trying to feed them frozen mysis one by one, but it's hard to be sure they are all getting food when we just squirt the cyclopeeze in.
With regards to the wildlings living in the tank with Quattro... last night I saw one of the babies on the wall between his two front arms, right up against his webbing. As he moved upward, the baby simply scooted forward too. Eventually, the baby jetted away, but there was never any attempt to catch and eat the baby. Minutes later, Quattro was all arms and ate hungrily when I dropped a couple of frozen mysids between his arms where the baby had been. Just one observation, but I wanted to mention it because of the previous concerns about your adult male D. Can't prove a negative!