Something similar to „Book of the New Sub?“

So I recently finished „The Book of the new Sun“ by Gene Wolf. I read the four main titles and really enjoyed it. Something about the world he builds, the writing style and the multitude of topics „between the lines“ really fascinated me.

So I’m wondering if there is something similar that I should check out?

I read somewhere that the next book that was published much later isn’t that good and doesn’t really fit in there, would it still be good read similar to the other ones? How about wolfs other works?

Thanks a lot!