I just pushed v0.1.0 to the code repository. The biggest change alongside all the SDK upgrade shenanigans is the integration with the vector_math package. dartbox2d no longer has its own vector and matrix library, but instead runs against John Mccutchan's library.
You may see some subtle differences in simulations, but nothing seems to be broken. Performance is comparable and in many cases better by a few percent. Now that we're depending on John, I expect performance to get even better, and I don't have to do the work (yay!).
I'm holding off publishing this to pub until John pushes one more needed fix to the vector math library, but as soon as he does, I will.