Ultimate Tax Exemption for WooCommerce

Hello,
I’ve been working with various non-profits so I added this plugin to my site. Most of my customer orders are manually built by me so they can pay as an invoice. The trouble I am seeing with plugins like this one is they seem to only work from the storefront and cart, not backend order management which is where I need it most.

However, when an order is manually placed by an admin or a store manager role there is no way to remove the tax from that interface (the shop is connected to WooCommerce’s automatic tax plugin). When the order is sent to the customer it’s put into pending status and the order cannot be changed, so they can’t see/use the tax exemption button. I am struggling with this and I think many others are as well.