Change offset values for only one axis at a time
When selecting two elements with different offsets, changing the offset value of one axis will cause both elements to also assume the same offset value of the other axis. For example, setting the y-offset value of two elements will make them have the same relative offset, but the x-offset value also changes, despite my editing only one offset axis. This happens when Automatic Placement is both enabled and disabled.
I think it is better to let only one axis change at a time, as this allows many elements to have a uniform (say) y-axis offset value. This is particularly useful when editing many rehearsal marks at the same time, as they usually all are at a certain height above the stave. All I have described worked as expected in Musescore 2, therefore I suggest that it retains this feature, or an option to enable only one axis-offset change.