Apply taxes by visitor procedence, not by it's direction in Prestashop 1.7.5

[Ina Blackwood]

Hello everyone!

I've recently started using prestashop and I found an issue I can't solve. I've searched for similar topics but they are not the same exact issue. I am about to start a tedious job on research and I wanted first to ask the community if someone has a good clue about where to start, or if they know a quicker solution.

The problem is the following: I started using geolocation in order to apply taxes based on the visitor's procedence, but I've noticed that prestashop uses the shipping or billing adresses in order to apply them (considering that the visitor is a registered customer) overriding the tax application based on geolocation. So, for example, if I am entering the website from Australia, but I've a billing adress from Japan as a customer (or just a fake adress from another country, considering that the product can be shipped to one of a list of physical shops), the prices are set not by the procedence (Australia), but by this address (Japan). 

When I enter in Taxes->Tax Options (in the Backoffice) there's only the option to apply taxes based on one of those two adresses. Is there any way to override that? I don't mind coding.

Thanks in advanced, and salutations.