Try the following. Bring two Heavies with GL and mounted launchers on any mission, except nests/bases.
Use a soldier with high perception to spot enemies.
If the enemies are more than 40 tiles away, wait for them to come to you. If they are under 40 tiles away, have the Heavies cast Boom Blast. You now have 6 artillery strikes.
If any enemies survive, use assault to mop it up.
Or wait another turn, and do it again, and then mop up.
It’s a template that works on most missions.
@mcarver2000 we have had this discussion many times. The existence of an optimal strategy shoehorns many players into using it.
Why bother with anything else if every turn each soldier can lob 3 explosive projectiles without LOS at a distance of nearly 40 tiles? (and that without going into stuff like Rapid Clearance, Adrenaline Rush, or the new Onslaught).
To be fair this is what was done with Quick Aim. On release it also provided a 25% bonus to aim, and it was definitely the right decision.
Why should Boom Blast provide both a reduction in AP and an increase in range?
EDIT: The point of my suggestion is to make Boom Blast deliver a single, very powerful artillery strike, instead of 3, so it would make sense to use it situationally against a large group of enemies/one large enemy, not to clear the map by nading individual enemies/small groups.