I was thinking along the same lines; but there's a potential problem in that this provides an incentive to mislabel a beverage's ABV to get a lower tax rate.

That's probably solvable-ish by fining companies found to have an ABV off by more than 1% or so, but that's a lot more work to monitor, especially with the number of different products on the market.

You can't (well, shouldn't) mislabel your beverage's ABV. It's trivial to test and thus determine that you're lying, and the result would be a hugely costly recall of all product.

The accuracy requirements are very strict on this. It's already not a problem; intentionally lying about ABV on the label would be a foolish thing to do that would get you in lots of trouble.

Similar statements can be made about insider trading or constitutional violations.

Not really. Those are much harder to detect and prove, and remedies have to go through the courts.

If improperly ABV-labeled alcohol is detected, it will be immediately recalled from all shelves nationwide, no court involvement necessary.

Labeled as 5% but actually containing 40%, sure. Labeled as 35% but containing 40%? No, because those are functionally identical for most consumers.

What’s new is that brewers now have legal teams to help them figure this out.