Requesting Changes on Large POs in iSupplier Portal

We are on 12.1.3 and our suppliers who use i supplier  portal to acknowledge and request changes to POs face the following issue .

In this example the PO  has 100 lines and  the lines are distributed over 4 pages in i supplier portal(we show 25 lines per page)

 

If the Supplier wants to request changes on this  PO on  say line#S 1,26,76 and 98 (these will show on page 1,2,3 and 4 respectively) , the supplier cannot make changes on all the lines and submit all the 4 changes in one click but has to follow this sequence:

1.Request changes for  line#1 on page#1>submit the change>wait for the buyer to accept/reject the PO>Request changes for  line#2 on page#2>submit the change>wait for the buyer to accept/reject  the PO