It definitely helps if you have one lot number when you develop a load. I've had different lot numbers not change the load at all, and I've had a 10% change in different lot numbers. Always verify your load when anything new is used (powder lot #, primers etc.).
Oh, I forgot to say that you use 1 of the 1lb bottles as your decanting bottle for the whole 8lbs, then do the same if you can’t get an 8lber again. Less chance that a 1lber will go bad if frequently filled.