I mentioned this in issue #264, but I decided put it here just in case.
Xaero96, the author of Xaero's Minimap, said to tell you this:

With the Chisel mod installed, getting the IBlockState straight from the world/chunk and using the following method:
Minecraft.getMinecraft().getBlockRendererDispatcher().getBlockModelShapes().getModelForState(state)
to get the block model does not return the correct model. It only works with states gotten from the state ids:
getModelForState(Block.getStateFromId(Block.getStateId(state))) works, believe it or not.

Wrong, we use that method in our own code just fine. I'm not sure what issue he is having, but it's not on our end.

Ok, thanks