Issues dealing with unordered products received

Almost all of our materiel suppliers invoice based upon their delivery notes, some even group multiple deliveries in a monthly invoice. We therefore have invoicing set by default at delivery for purchasing.

The problem is Tryton seems to only generate an invoice for deliveries tied to a purchase order and not to the receptions themselves.

The simple scenario I ran into today was a case where we passed an order with some quantities changed and a couple items removed from the sales quote. Unfortunately the supplier shipped us the originally quoted quantities.

In the reception, now I have too many of some items, too few of some others plus, of course, those we didn’t order.

Tryton seems to handle very well the back orders, but not necessarily the extreme cases.
In particular, the generated invoice is missing the products not ordered at all.
Also, when receiving, there is mention that the origin is missing which, in this case, is exact.

So how to better deal (track) these exceptions, perhaps a mechanism to auto generate draft returns in the purchase order exception handling? Unfortunately, there seems to be no way to link back to the PO itself only a PO line (which permits the case of extra delivered quantities of products to somewhat work).
This should also permit the invoicing to work correctly as it would be somewhat tied to a PO permitting following the invoicing method chosen.

Has anybody already worked this out and fix it?