I would like that next bar to be condensed with one stem for both flutes. No matter what I do, that’s not working.
If I try manual condensing, then it just affect the slur before
With the condensed score in engrave mode, select the three up-stem dotted half notes and press F to flip their stems. Then select the ties between these notes and press F to flip them upward again. Finally, select the three down-stem dotted half notes and set their Voice column index property to zero:
