Some people come back in and have coordination trouble for example. Bumping in walls, grabbing stuff with "ghost" hands, etc... Headaches too. Not everyone though.
Good point. Also, some people get a bit "freaked out" by ext/int.
I've encountered non-scientologists who've had oob phenomena, sometimes spontaneous sometimes as a result of an event or "incident". These individuals to which I refer subsequently had significant problems which were directly related to the prior occurrence. It often is compounded by an inability to communicate about the experience due to "out reality" of others or even himself. A bit of auditing on ex/int can clean up a lot of charge for such a person.
Also keep in mind, potentially any traumatic experience can be "restimulative" of other similar experiences. If you are open to the "past lives" argument, everyone who has experienced prior lifetimes has experienced previous ext/int phenomena often in difficult or traumatic circumstances.
Hence, ext/int is a likely subject for chains of incidents associated with prior life traumas which may get restimulated and interfere with whatever specific case issues are currently being addressed. Or then again not, depending on the individual.
Mark A. Baker