What was the reasoning behind going from eight weights to six (i.e. dropping Book and Ultra Black)? I’d be curious about that.

I didn't think it was necessary to have so many.
Thin is still Thin, and the same weight as before. Ultra Black is now renamed as Black. I renamed it as I didn't think the original Ultra Black warranted that title. Besides, Precious Sans Two is a complete rework of the original Precious Sans and a vast improvement, so I wanted to differentiate the two.

Makes sense. Thanks for the explanation!

Good rework Nick, congratulations! I like it.