Hello
I had the same requirement. Unfortunately enhancement spot in MODULE fill_tc_mr1m in INCLUDE LMR1MO1H was not relevant as DRSEG table is still empty at this point.
But I found an enhancement spot in include LMR1MI3W where DRSEG table (YDRSEG) contains SAP proposal and we can update this table here.
It works fine for me
Hope this helps
Jean-Michel