Receipts Routing and Lot Number

Hi,

I have a client who is using Receipts Routing and would like to use auto-assigning of Lot Numbers (via next number) performed at the In-Transit operation.  I have not used RR before but my test indicates this cannot be done at In-Transit.  The Lot Number is being assigned during the Commit to Stock.  Is this functioning as designed?  Is this because that is when On-Hand is updated?  Is there a workaround/set-up changes that can be done to have the lots assigned at In-Transit without customization?

I would appreciate anyone's help!

Thanks!