Did we ever get clarification on this?
Nope.
At my table we do it like this:
If you have
FA mode and want to hit multiple people you select a triangular area projecting from you outward up to a distance of your choosing, up to the maximum range of the weapon, with a width of 10 meters at its end and a height of 2 meters (a frontal cone attack). Then you make an Automatic + Agility [Accuracy] Test, including bonuses for smartlink, laser sight, tracer rounds, and other gamemaster-approved modifiers, and record the hits. The area attack lasts until the end of the Combat Turn as long as you don't move or commit to any other action (so you can choose to end it early if you like).
Anyone (friend of foe) in the fire zone takes a dice pool penalty to all actions equal to your hits. Anyone who is in the area (but not behind cover or prone), or who moves into or out of the area before the end of the attack, risks catching some flying lead. They must make a Reaction + Edge Test (+ any dice they may get as a result of choosing to use Full Defense) with a threshold equal to the hits scored by your attack. Note that in the test, they use their full Edge rating, regardless of whether they have have spent points during the session. If the test fails, they are hit hit, suffering damage equal to your weapon’s base Damage Value modified by any special ammunition being fired.
Everyone in the area who remain behind full cover or drop prone are not at risk (though they suffer the normal modifiers for being prone; see Melee Modifiers, p. 187, and Ranged Modifiers, p. 173). They may choose to avoid rolling and use their Free Action to go prone and avoid getting hit. Someone that does not have a Free Action remaining may use the Hit the Dirt Interrupt Action and go prone instead of getting hit. Any one who stands up or moves again before the attack stops must make a test to see if she is hit.
According to the Firing Mode Table on p.180 the attack cost 20 bullets and does not cause Recoil.
All this is RAW and covered in detail on p.179 and p.180 under Suppressive Fire.