TN Tiered Taxes

So I’m developing in a BC 365 19.5 US on-prem environment. Trying to handle Tennessee, USA sales taxes. Which are a bit tricky. They are tiered and are based on the individual line items. I’ve found an EventSubscriber endpoint to listen to in order to calculate and override the sales taxes. But these are being applied against the sum total, not against the individual line items.

Here’s a link to a post I made over in the Microsoft Dynamics Communities regarding more specifics → Codeunit::"Sales Tax Calculate" EventSubscriber? - Dynamics 365 Business Central Forum Community Forum.

Anyone have any insight or suggestions? Since we are on-prem and a few versions behind we are having trouble finding a third party add-in extension to just take care of these taxes automatically.