STO with multiple Schedule Lines will not modify them if new stock becomes available

[calancs]

I have an Intercompany STO with a qty of 1000 due on Oct 10.  I only have 900 in stock and a future PO for another 500 due on Oct 30.  The STO creates a single schedule line for 1000 and confirms 900.  When V_V2 is performed, a second schedule line appears for the uncommitted 100, with a date in November.  This occurs because the availably check is set to use future POs.  Again, this activity is all expected. 

Then we call our vendor and get the next delivery expedited to an earlier date.  The PO delivers early on Oct 01.  we now have 1400 units in stock, but V_V2 will not change the scheduled lines to meet the original requested due date.  It seems to look at the two schedule lines and confirms it can meet them.  My only choice is to open the STO and manually change the schedule lines.   This is fine for 1 STO but this manual intervention is not effective for the entire plant. 

Is there any way to get SAP (ECC6) to change the schedule lines to meet the original due date of Oct 10, now that we have Stock again? 

The STO requested 1000 on Oct 10.  The current Schedule lines will deliver 900 on Oct 10 and 100 in November.  This is not desirabl.