Just a side comment:
There is nothing that a hexflipper loves to see more than gangbang tactics, they play directly into the hexflipper's hand. Rather than having to worry about 3 enemies to avoid (if he is seeking to avoid them) he merely has to contend with one group. The idea of gangbanging as a defense vs hex-flipping is silly. Now what gangbanging does do is to drive off single pilots who are looking to fight from a hex.
As far as the disengagement rule and hex flipping, it usually is no deterent and rarely has any rel effect on this at all with the exception of particularly important hexes VC hexes, planets, bases, etc. 90% of the time an equally relevant target can be found elsewhere. This is hy I think multiple DV shifts or not the DR needs to be eliminated in open space but extended to apply to all hexes surrounding a base or planet s if they all were a single hex. This is contigent on how large the map is and wouldn't work on a small map.