I'm close to where you are in terms of SA, so I figured this might be relevant to you (I have had enough AP to get my third SA, but I've been working on getting my third Insane artifact before I do).
I've played all of the "new" levels a few times, just because I enjoy playing. You can read elsewhere, but the AP doesn't warrant farming them much. So from my perspective, worth the time if you like new challenges and get bored going through the same levels, but not worth it if you get frustrated with your progress slowing.
I have not unlocked SuperCamp, so I tend to use powers in the beginning of the levels to get myself going. Superpower IM is great when you find a big merc camp. And that typically helps me close out levels.
https://pkmx.github.io/wzi-levels/ is a helpful resource. And I know I have seen walkthroughs for these levels, but can't find them offhand.
Hope that at least helps a bit.