Here is my grain of sand.
From my experience with the GZ Test 1, I have seen that the damage can depend quite a bit on the awareness of the target. We have to remember that there is around four seconds of delay on the bomb drop. When the BB is reacting to the dive bombers with the same trepidation it does to torpedo bombers, (by turning hard to one side), the maximum damage output I managed with all the alpha strike is 25k. Unfortunately, most players are not aware of the danger that the dive bomber has, and keep sailing in straight lines. In this case the damage dealt gets around +50k.
The alpha damage is spectacular, and the impression on the victim that did not manage to dodge the drop can be a bit overwhelming. That said though, the overall damage is lower compared to other carriers of the same tier. One has to remember that penetration damage can be healed up to 50% while torpedo hits counts as citadel damage, way more difficult to heal. Not to mention about the lack of damage over time that carriers with torps and HE bombs have.
The tl;dr version of this boring explanation is:
if you play on a BB and want to avoid the alpha strike of the GZ Test 1, just turn hard the same way a cruiser has to do to avoid getting deleted by your guns.