Each Improved Acid Flask costs 0 gp to make. With the Equipment sphere dedication, the alchemist's swift alchemy, and an alchemist's lab, each takes only 1.875 minutes to create. Thus, the entire batch of six takes 11.25 minutes to create.
During a long rest, the character uses the sharpen weapons maintenance, giving the entire party a +4 untyped bonus to all damage rolls made with manufactured weapons. Yes, even if someone in the party picks up a weapon from elsewhere; the blacksmith is just that good.
When combat starts, the character uses Cluster Toss to draw and throw two flasks, then uses Snap Toss to draw and throw a third flask. The character targets a single grid intersection, which is only AC 5, and will thus miss only on a natural 2+, even if they are throwing out to 120 feet.
The result is a deadly blossom of unavoidable acid damage, no saving throw required.
How powerful is this "nova"? We are looking at 7d6+12 (average 36.5) × 3 acid damage in a 20-foot radius, then half that much damage 5 feet past that radius, and then 7 × 3 acid damage another 5 feet away.
What can this take out?
Against enemies without acid resistance, this produces 109.5 acid damage in the central 20-foot radius, enough to kill average CR 8s or 9s: docs.google.com/spreadsheets/d/1E2-s8weiulPoBQjdI05LBzOUToyoZIdSsLKxHAvf8F8/edit#gid=3
Against enemies with acid resistance 10, this still generates 79.5 acid damage in the central 20-foot radius, enough to eliminate CR 6s or 7s.
As well: "Targets who take at least 2 points of acid damage from the initial attack take half the total damage again on the following round."
Therefore, this can actually take out a 20-foot radius of CR 12s or 13s without acid resistance, or a 20-foot radius of CR 9s or 10s with acid resistance 10, if the character is willing to endure a one-round delay.
This is still completely excessive, particularly considering that it is an area effect that almost always hits on a natural 2+.