When a detonation occurs does the steel tube get damaged?
The dillon kabooms I've seen pictures of, didn't indicated damaged blast tubes.
The key difference between a CPS and a progressive press, is the shear force applied without the users ability to necessarily feel it happening. It's not super hard to apply enough force to crush a primer with a 2ft steel handle on a progressive loader. As that handle is moving, a lot of other things are moving, so you can't really feel much. From my understanding, its possible for some primers to get sheared off as they fall from the tube crooked, and due to the primer being crushed right there beneath all the rest, it sets the stack off. That's at least my understanding of how those incidents happen.
With a CPS, the primer is moved by hand, which is near effortless, so if something is not right, it can be felt immediately... and even if a user isn't very attentive, it would be really hard to apply enough force to the shuttle system with your fingers to crush a primer in that position. It would indicate wild negligence in operation. After the primer moves into the shuttle and the shuttle is moved forward, it is completely encapsulated and segregated from the rest of the primers in the tube. Once in forward position, the primer is then lifted up and even further away and more segregated from the primers in the tube, before seating begins taking place. The shuttle in the forward position, further blocks the pathway to the rest of the primers.
The primer tubes must be cleaned regularly to ensure no unsafe buildup of material occurs, just as with all primer tubes.
The RCBS bench priming system is a good comparison. Fully exposed tube, that flops around a bunch no less. The CPS handling of primers is quite gentle in comparison. We have commercial ammo manufacturers running these tools in shifts, around the clock, and they rave about how safe and efficient their people feel when running them compared to other systems they ran previously.
Though as I said, if a user would like a metal tube around the primer tube to help calm any fears... one can be provided.