The Wand of the Forest currently allows you to shift+right-click on a block to rotate it on the clicked face, if that orientation is supported. E.g: furnaces and chests only rotate on the vertical axis, pistons will rotate on all 3.

Slabs do not currently respond at all. On the one hand, that makes sense...the block does not change position, they are in fact a different block. A bottom-half oak wood slab is 126:0, a top-half oak wood slab is 126:8. The different types of wood are similarly different metadata, 126:1 is spruce bottom, 126:9 is spruce top. This function is useful in a Garden of Glass pack that doesn't include tech mods, specifically Thermal Expansion, when working with platforms that are build from half-slabs to prevent mob spawns.

In IRC, I was told the following: it really shouldn't be, we include that in CoFHLib and anyone is welcome to use that class in a wrench-style mod

So, given that it would either require re-inventing the wheel, adding a dependency for that ability on including CoFHLib/CoFHCore, or (if it's available via API) adding an API to the mod, maybe this is not a reasonable request.

Is this ability not a simple request? Does it not fit in with the way everything else works? I would still like to see the ability added to the rotation ability added natively, without requiring an additional mod, especially one as heavy as Thermal Expansion. I understand now.