Can the Checkout Page pull in external sales tax information and apply it through the Checkout API?

What’s a shame is that the base Shopify plan doesn’t fully support sales taxes and whatnot right out of the box. As a potential customer, we shouldn’t have to pay for an upgraded POS plan in order to do something as simple as correctly calculate Tennessee tiered sales taxes. But that’s the way it is. I’d imagine the same could be said for non-US VAT structures and whatnot…