When someone else fronts, I don't remember much of what they experience, if anything. They can draw on my memories, mostly, although I can wall them off. I can sort of draw on theirs, but it's hard. It's hard to explain. It's not a hard barrier but it's there.
I have to remember to tell people when I've switched back; that happens if someone has fronted for too long and has gotten tired.
Sometimes we have blendy moments where co-fronting happens with me and another.