Here's an image of Morado (From Atmospheric, boards by this mod) and Spruce (from AP itself):

Morado has odd_x and odd_z blockstates, but they do nothing, while spruce doesn't.

I see that #160 has a comment that it should be working a while ago, but that change is not reflected in the code - BoardBlock is used here and the mentioned function for registering dynamic models (registerBoardModel) is unused as far as I can tell.

Today I fixed this on AP's side for the Forge version of the mod (as seen here). The update should be out relatively soon.