At this time the Apply Tax button on the POS screen will remove tax from all items in the sale list. I was thinking there would be a way to get around it, but it appears that the only way to sell a single item without tax is to ensure the item itself is setup as non-taxable in the inventory.
We need to allow for toggling tax on selected items as well as the entire sale. The most intuitive option may be to simply click the cell in the POS list to toggle. We can also add the option to the Item Details form.
Added in version 184.108.40.206. Sales tax will now be adjustable using the following form. If there are no items in the list... the sales tax toggle happens as it did in the past (no form).