In section 3.4, the authors mention that it might be possible to do something smarter than the simple round-robin approach to measurement ordering. This seems to be an acknowledgment that some error could be introduced for some kinds of motion by always listening to the measurements in the same order - this problem is also present in traditional systems, and it's interesting that there is an opportunity to correct for it here, but they don't do it. It seems like even random choices for the next observation to use would be better than round-robin.