Is the military changing any of their disciplines to stop elevation of muzzles over back-stops???
No. Military troops are well disciplined and well supervised in firing range operations. On most military ranges it matters not if a bullet sometimes goes over the berm because no one is allowed down range to the maximum range of the round being fired.
The vast majority of military outdoor small arms firing ranges are located on large installations where the government owns the land past the maximum range of the weapons being fired there. That is a requirement of new military firing range construction. A few military firing ranges are built on shore
and the bullets impact in water. When the range is hot bouys are set out and MPs patrol the area.
BTW: The maximum range of a M80 7.62mm military ball round is 4,100 meters.
The surface danger zone of a firing range is shaped like a fan. See page 15; figure 3-2 and page 25; figure 4-1.