I’m not with the idea but I’m not against it either. Personally I can do without any extra step but let’s give @gxtsoft a chance to lay out their case.
Let’s see what’s to be achieved? What are the effects of this proposal on Manager? What other software are doing? What are the costs and benefits?
The date of the valid invoice. You have not yet answered the key question on fiscality either. You give examples from Costa Rica, which is interesting as I lived there for a while and the last example is a SAP entry that seems to be related to Netherlands transactions and I am very familiar with the system there and maybe you can seek advice of @ries how this works well in NL.