Maybe I'm being too picky, but the wording suggests that all non-movement dice should be ignored. Here's my suggested approach. It may be overkill, but it's cleaner, and I think it should cover all the points that have been raised.
- Classify all dice as movement dice or effect dice. Movement dice only permit movement. Effect dice have other effects. For the purpose of supporting effect dice like the Mini Monkey Bones, effect dice can also cause movement; however, the amount of movement on effect dice should be kept limited.
- Further classify all the movement dice as forward, backward, or bidirectional. Forward dice only permit forward movement, backward dice only permit backward movement, and bidirectional dice let you choose a direction for them before rolling them.
- Movement dice can only be rolled together if their directions match.