The Edit Mode Options panel has been a rather random grab bag of mode-options, many of which had no relation to each other.
This was recently improved in a08fb46700a3 by moving the edge edge-tag option from the scene into the operator.
Still, it could be improved further. This is the current panel:
This patch moves the Live Unwrap button to the UV menu:
And then re-organizes the Options panel a bit: