To avail this kind of addition you have to customize the plugin. But I am really sorry to say that we do not provide any customization services. If you need this option very urgently you can hire a developer you can do the customization on your own if you know how to programming.
We did not keep tax based on shop address for some reason. One of the reason is:
Suppose, there are many sellers in a site. Those sellers are from different country. So when a customer wants to purchase several products from several seller then each product calculate different tax rates. That will create a negative impact on the business.
But if you want to add this feature in your system you have to customize the plugin on yourself. To customize the plugin, you must have a good programming sense. If you do not know programming very well then you can hire a developer.
Yes, That's what I mean.
I just did not Understand the question and your answer.
You just can do tax calculation based on the products tax rate and the customers address, but neither on the store address nor on the sellers address.