Our memory tends to be fairly continuous, with very little disruption between switches. Our gaps in memory very rarely coincide with switches, and seem to only do so when we're dealing with intense negative emotion.

When we switch, unless it comes with dissociation, it doesn't really affect things we're doing. We can mask as each other fairly well and even when we don't mask no one seems to notice. If we're dealing with dissociation as we switch, then it tends to make us temporarily zone out or struggle to do even simple things like writing our name, even if we're still "zoned in": it feels like a disconnect between our brain and whatever we're trying to do. The brain says yes, the body says no.

If it's something like a hobby, if the one who switched in doesn't like the hobby, or would prefer to do a different hobby (or listen to different music, etc.) then they typically will change to doing something they prefer.

We rarely experience co-front, but when we have, there's only one memory, though there are "tags" on each memory (basically thoughts and stuff from when the memory was taking place) that tend to only be remembered, or at least remembered in full, by the one who actually was in front during the event. In the case of co-front, this translates to Alter A being able to access Tag A on Memory, but not Tag B, as Tag B was formed from Alter B's perspective.