AI is not recommended, the main reason being... it often looks bad! If something looks AI-ey, it'll likely be penalized due to the low quality vibe that AI tends to mask things in. Not even necessarily because it IS AI, but because it just isn't as cohesive. If you are able to use AI and hide it well enough, it'll probably not be penalized. 

Even if I wanted to enforce a no-AI rule, it wouldn't matter because people who are good at using it will hide it well enough that the judges wont notice. And if the AI is noticeable, people will generally not like the product as much as a hand crafted one.