Currently the cash discount calculates on the document total, which includes taxes.
In many cases this is an incorrect way to calculate cash discounts, where it should be on the base amount only.
It should also be possible to toggle whether freight is included in the base applicable for cash discount or not.
Applies to AP/AR/SOP/POP
Unfortunately the application does not provide a setting to control how the cash discount amount should be calculated. It is however very easy to customize by overriding the Terms attribute, and we are providing the customization to partners and customers who require that functionality - package is available at https://gist.github.com/smarenich/c9e94c556d6e0601d3d229d80e540bb7 - just upload ZIP file and publish. The customization works for non-inclusive taxes in AR and SO invoices and in purchase orders and AP bills; the taxes should have Does not Affect Taxable Amount or Reduce Taxable Amount on Early Payment option.
We are still considering adding the ability to control that behaviour through a setting.