Shipping Zones - Option to set the MIN & MAX sale total for each shipping threshold in various currencies

Would like to have a shipping zone revenue threshold be available in more than just the base currency in my case $CAD.

For example, I am setting a free shipping threshold at more then $300 (if the customer orders less than $300 they must pay for their shipping).

If the customer is a USA customer, they in fact get free shipping at a sales order value of less than $300 since currently, the $300 threshold is only available to be set as $CAD (being the base currency).

This defeats the purpose of having the shipping zones and rates based on a certain threshold if your sales are being generated in multiple countries.

Here is a screenshot. Let the $CAD be changed to other currencies so that it becomes customer specific.