Hi!
Try this using partial confirmation:
While confirming the order, let the consumption lines for components (if you have) with movement 261 as it is. It will decrease your stock of components as used (even for scrap part), so no 201 movement will be needed anymore.
Then in the line of the good issue with movement 101, edit to bring only the "good" pieces". This should decrease only the good parts from the total order.
When you finish the order, do the opposite: edit the 261 lines to increase your consumptions as phisically done (enough for 1 more piece, in your exemple).
Then in the 101 line, keep as it is (the remaining pieces only).
If you use this, and in your last round select final confirmation, I am pretty sure that you will get the result you are looking for...
Marcio