In particular, I'd like to have the possibility to get:
* Fungi stems (warped and crimson), as well as shroomlights. (And to a certain extent, wart blocks)
* Blackstone, and in particular blackstone bricks (since they mine faster than "raw" blackstone, and also you save a trip to the stone cutter for each stack)
* Nether bricks
Other nether material (soul sand, magma blocks, nylium blocks) tend to be more abundant in the nether and needed in smaller quantities, so they are not as important.
I know the farmlands traditions is to keep different farms for different materials, but I'd be just as happy with a general "nether" farm with two kinds of forests, a partial forest and a partial bastion, or something like that.