It might have just been an off-day for folks but from what I saw last weekend, all the candidates for the next black belt level, myself included, do not seem ready for their next test. As cutting criteria again, you need to be proficient in those cuts, which to me means you should be able to do it not just once or twice but pretty much on command 60-90% of the time.
You should not have to think through the cuts but you can certainly do it at a careful pace (slow in between cuts). The worst is when you try to cut while thinking about your next cut. This is what causes mistakes for most students: in thinking of the next cut, you move too quickly into position, while your current cut is in flight. It ends up with goza off the stand, shakkuri, or other errors.
The other part is performing under stress. A busy environment like the park last week is distracting, but a test situation makes it even more stressful. It lowers your ability to some degree.
So far, I don't have that for 3-goza cuts (at least on the kesa giri part). Based on Saturday, it doesn't look like people have that for some of their patterns. So I'd say practice on air many, many times, with speed and power, before you try it again.
With 1 goza that is quite doable. Most times, I don't even feel the impact of hitting a single goza anymore. Unfortunately the "hardness" (not difficulty) of multiple goza is not something you can mentally replicate easily. For multiple goza, the only real way is to just do it on real targets over and again.