Autoselect the closest expiration lot/serial

[HDeriauFF]

Well, after a lot of research and analysis, I did it: it's all about manipulating the cart's sessions values and arrays using the SerialItem class. The solution in itself is quite simple and does not require a lot of customization, everything fits in 40 lines of code
It handles all situations the same way ConfirmDispatchControlled_Invoice does.
Available quantities are automatically selected in all lots (I use the PO line during order entry to indicate which minimal expiration date is acceptable) rolling over through the next available lot if quantity needed exceeds the lot quantity, and indicates directly on ConfirmDispatch_Invoice which quantities have been picked in each lot, if complete or partial.
Everything of course is still editable accessing ConfirmDispatchControlled_Invoice.
Screenshot of the modified page (showing what we see when we land on the page, without any manual intervention)