Quote discount % or amount

I am a little confused by the Quote Discount % or amount. I can see that if I put a percentage or amount in and Save the Quote, the subtotal remains the same, the Tax amount stays the same and only the Total is changed to reflect the discount.

Should the Quote Discount not be cause the Subtotal to be discounted and trigger a recalculation of the Tax based on the discounted Subtotal. The way it seems to be working, we are charging too much tax.

Or have I missed something?

Quote and invoice donations are subtracted from the subtotal + taxes. I recently planned to add an option to calculate the discount before the taxes but I couldn’t manage to get it working correctly.
If you want to give a discount on the subtotal without tax please use the item discounts.