Comments
To take it a step furhter I think the choice of mail address and layout should be separate customer linked setups. Often customers have only one layout for order confirmation etc for all customers but do want to specify different mail addresses for different document types.On Topic there could be a setting like with options like To, CC, BCC, Ignore Document Type Sell-to/Buy-from Bill-to/Pay-toOrder Confirmation To IgnoreInvoice CC To
I recently opened a support ticket for this issue (as well as hide/show logic not rendering either) and support reported that this is due to the current form renderer not supporting business rules. I was told to use custom handlers on the form canvas to achieve the desired functionality. If MSFT is not going to enhance the form renderer to support business rules, there should be more clear warning or blocking when building business rules that knowingly won't be supported.