I am a singing teacher. I work two short days at a school. I pump once while there. I notice lower production after my long day t work when I pump twice( 7 hours, thst turn to 10 when I add the commuting). My DD is 6 mo, and is on BM only. She takes 4 80-120 ml bottles. On FRidays I notice less milk flowing down. I use a manual Avent and an electric one. I could be happier with the electricone, but...prices are high of the Medelas here in BUenos Aires...
I could start taking domperidone. I used it to wean DD of mixed lactation(she was premature)...but thought of maybe your ideas could be better than meds.