This fire control measures and engagement priorities have been the subject of many lengthy discussions since at least June. Putting these in requires a top to bottom redesign of combat resolution. That is why such things are going into the next engine. Code-wise, there's a lot of discovery to be done to determine the "art of the possible" for a timely release.
Having said that, here are the concepts we are looking at:
1. Sector of fire: two adjacent hexsides
2. Engagement Area: the player defines a polygon on the map. Established during setup before starting the scenario.
3. Commence fire line or commence fire range
4. Engagement priority (pick one): Default, indirect assets, engineer assets, C3 assets, air defense assets, recce assets. We would likely define a range at which a unit ignores this and shoot closest targets for self-preservation. In-hex for sure. Maybe out to 2 hexes.
5. Attack by fire position
The Default priority would be something like greatest threat (enemy unit has anti-armor capability), near to far. Of course, units would fall back on the Default if there are no targets matching the unit's priority setting and self-preservation overrides all.
Again, this is a set of concepts being considered, not a feature list.