there really isn't much that needs explaining, this would just add more room for creativity and just make the game more polished.
I support, as long as mixed wood is still allowed. (It could just produce oak shelves.)
I want ocean content(thanks Möjang!), nether biomes(again thanks!!), and savanna passive mobs (meerkats incoming!?).
Mixed wood just kind of defeats the purpose of implementing the different kinds.
Is mixed wood permitted when making fences, or doors or slabs or trapdoors or ...?