You do not want to skip flash-freezing the peaches on the baker's sheet individually. Trust me. I did it the very first time I froze peaches back in 2009. I was left with a big solid block of peach mess. I couldn't get it out of the bag! After I cut the bag apart I couldn't do anything with the frozen peach block until it completely thawed. And then everything was a mushy mess. So definitely freeze each slice individually first in the flash freezing section.