When you are editing multiple targets in merged multi-editing mode, and you adjust the value of any drawer target by dragging its prefix label, all values will be adjusted separately from each other.
This is different from how the default inspector works, where all targets are set to the same value when you start dragging.
Full Undo Support
Even in this complex scenario there is full undo support, so all you need to do is give a single undo command, and the values on all targets are reverted back to the states they were in before you started dragging.