Triangular transactions between European countries is a common process. There are lot of transactions requesting direct delivery inside European countries.
System is not taking into account local requirement
• Sales tax report should be different
From Example in UK, UK VAT report should not include sales payable on box 8 if transactions is triangular.
• EU sales list should tag transactions as Triangular/EU
• Intrastat should tag transactions as Triangular/EU

Setup can be done manually but it is difficult for user to know when to change setup, but also not possible due to volumetry.

Suggestion
Automation of triangulation business has to be considered as all information are available
• Legal entity country = EU
• Customer country = EU
• Warehouse Country = EU
• Sales order is marked as direct delivery

In this case Foreign Trade parameters on sales order header and line should be Triangular/EU trade

When foreign Trade shows Triangular/EU trade, option to change sales tax Group should be possible as Reverse charge rules setup for specific item.
This reverse charge rules may be enhanced and take into account triangular transactions.

Another possibility will be to have Term of delivery with option warehouse that will impact sales order to pick sales tax group from warehouse. So far it is only possible for Purchase order.

Completed with this Idea
https://experience.dynamics.com/ideas/idea/?ideaid=898e41d7-4375-e811-9cca-0003ff68c381