I don't think that they are eating the cyclop-eeze.
Too small, not moving and such.
I have seen newly hatched cuttles strike at RN Tigger pods (essentially live Cyclop-eeze), but only for the first few days. After that they ingnored it. I also tried Cyclop-eeze, but didn't see any interest.
At two days I see baby cuttles strike at amphipods, which sometimes get away. However, I have never seen mysids given at the same age get away from the baby cuttles.
The only food I have seen baby cuttles eat without hesitation in front of me has been mysis. When I fed amphipods, I almost never saw them strike.
I have no idea if a varied diet would be more beneficial to baby cuttles or not - especially if we have no way to tell what they are actually eating and what they aren't eating. My feeling is that it is more important to get them the food they will eat most that is most nutritious, and so far that seems to be mysis.
Now, I could be wrong about the cypolp-eeze, but since you are feeding with a kitchen sink method there just isn't any way to be sure.
The only reason I bring it up is because I worry about people deciding to raise baby bandensis on cyclop-eeze based on your report, but the reality being that they aren't actually eating it. People are still trying to raise them on enriched brine and having dismal results because of old, persistent reports of it being a suitable food. Anecdotal evidence has been a major problem in other areas of the saltwater hobby, so I am cautious when I see it.
Like I said above, I have stopped with the amphipods and switched to just mysis starting a couple days after hatching and the growth rates I have seen have been amazing. Its also neat to see baby cuttles catch mysid after mysid after mysid which chewing on the first mysid.
I have also been rethinking my stance on net breeders for the reasons you mention. I recently built a baby nursery - basically a small tank plumbed into the main system - with a sand bottom, and I have seem more activity from the cuttles in there than I ever saw in net breeders. The net breeders do make a great, convenient way to keep baby cuttles in a larger tank, but perhaps the constantly exposed nature of the container make the babies uncomfortable (hows that for anecdotal!)