Never heard of a booster in a dryer vent and I wouldn't recommend one if you could put one in because it would just be something for lint to snag on to. I wouldn't mess with it unless your pipe is plugging up and then I'd say run it out the side of the house on a short and straight run as possible. Flex hose has crevices in it that catches lint. Use metal ducting with no screws, etc for lint to grab onto. Sometimes dryer vents need a rodding to get the buildup out. If you have much lint bypassing the screen, then it may be time for a new dryer.