Hello Anupam,
Your understanding is slightly incorrect on TQA concept w.r.t BOP. FYI...There will be a TQA that gets generated during BOP run but once the sales order CIF queue is dispatched, the TQA will not be there anymore because the CIF queue already has the confirmation details and it will be sent to ECC system for udpating your sales document. But, at this point in time, the Live Cache would not have the updated document information until the acknowledgement queue comes back to gATP system and updates the Live Cache. At this moment, the BOP status would get turned from "U" to "X".
On the other hand, when you create / change the sales document in ECC ( VA01/ VA02), there will be a TQA holding the confirmation and it will be deleted and the sales order information will be updated in LC once the CIF queue comes into gATP system.
Hope this helps
Babu Kilari
SCM APO GATP Consultant