I believe I read in Storeys Guide to Raising Ducks that as the duckling grows, the internal temp of the egg raises on its own over like the last 10 days. I decreased my temp .1 degree each day for 10 days, so 1 degree over all. I haven't read that about chicks but I assume it would be similar. I decreased my chicks .5 degrees.
Because of the advice I got on here, I ran the humidity low throughout the first 18 days. Never higher then 40%, average was 35% and I had a nice decrease in air cells. What were you running over days 1-18? Just something to think about for the next incubation. I'm not sure about your lockdown question. But I just wanted you to know, I know exactly how you feel! I wish you the best of luck and hope you get lots of fluffies!!