My invoices regularly require shipping or freight (which is my only pre-made store item because everything I sell is custom) but you don't have a way to apply that separately on an invoice, similar to but after the discount and tax. Because I have to add shipping or freight as a non-taxable Item the discount gets applied to its value as a percentage of all items, which is SO WRONG! Alternatively, I chose a fixed value discount instead but then the tax is incorrectly calculated because even as a fixed value the discount is being applied to all items rather than just the taxable items, AGAIN SO WRONG!
If the discount could be applied to only the taxable items it would be somewhat of a fix because then the tax would be correctly calculated and I could then use the discount feature. ARGH, SO FRUSTRATING!
