That may be true for your example as it is a random number. However, I have an invoice total of $650.00 with a combined sales tax of (4.75% + 2.25%) equalling 7%. I am using Dubsado online platform which calculates the total with tax to $45.50. But QB 2020 Desktop (and all versions prior) calculate the tax to be $45.51. Making the final total to be $348.01 instead of an even $348.00. 

Also, you mentioned that QB balances out for each quarter. But that isn't so, as I've been collecting excess tax (and remitting it) for years now. So no, it doesn't balance out. What it does is cause me to have recalculate my sales tax because when I put my total in form NC-500 it gives me the non-rounded up (actual) tax, which means I have to double check my numbers because the sales tax that QB is showing that I have collected is over what the NCDOR says I owe. As you know even pennies make a difference in a balance sheet. 

Yes, I would rather owe the money and have collected it, instead of vice versa, but this make it a pain when trying to keep two sets of books. Something that online software has made a really difficult to manage.