Mainsail is in-mast, so no drag difference whether furled or not. The headsail was reefed, so a 3-4cm rolled section would disturb the airflow more on starboard tack, but just the leading edge wasn't laminar - I would be amazed if this causes a difference of over 20% though.
I've just spent the past couple of hours trying to repair the work that the yard did on my ship
At least I'm attached to power for the first time in a week and have the air cranking while I'm head down in the bilges.