$0 tax when merchandise + discount total is $0

When we send out free product as a promotion, we typically add the merchandise to the invoice and then add a discount of the same value that zeroes out the invoice. If this promotion happens to be going to a taxable customer, even though the merchandise + discount will total $0, the sales tax often will not be $0, it will be 1¢ or 2¢ or 3¢ which ends up creating a small receivable balance for the recipient when it should be $0.

Can the Avalara integration be tweaked so that it checks to see whether the merchandise + discount total is $0 and if so, it overrides what Avalara may provide for taxes and gives a $0 result. Avalara rounds partial cents in favor of the state so increases the tax slightly on the merchandise, and decreases it slightly on the discount amount which is why these small balances appear.