Chucking is a physical phenomena, when you have uncoupled entities exerting unequal forces upon each other. The fact that you have a hitch in between means nothing, the truck and the trailer are two different entities held together by the hitch. Here's where the "fun" begins. You typical pickup will weigh between 6-8,000 pounds, an equal weight fifth these days is an entryway clunker, most better fifths you'll see are around 12K and they go up from there (sky's the limit). You hitch up 16-18K fifth behind that pickup and you have 2-3 times weight differential coming into that pickup and acting on the truck's rear suspension (through the hitch pin). Second, the fifth typically has much longer wheel base compared to the truck so it responds to motion differently. Thirdly, the brakes on the fifth are nor coupled directly to the truck brakes, you can fiddle with the controller to try to match them (in response time) but you can come close only at certain speed and certain brake pressure, the minute you increase (or decrease) the speed from the set point the adjustment goes out the window, the minute you put the hammer down hard, the adjustment goes out the window. Which means there will be typically a time lag before the brakes on the fifth start reducing the force vector pushing the truck. If you set the fifth's brakes on the aggressive side you will get the opposite, a jerk back.
We instrumented a hitch pin few years ago with a strain gauge,
to see what kind of forces we could see on the pin, the fifth and the truck during pulling, starting and stopping. There is a lot of weird stuff going on there and there is anywhere from two to three (or more) up and down and forward and back cycles before things settle down after any "disturbance", going over dip, pothole, braking or even just getting off the gas.
The bigger the truck/trailer weight differential the bigger the chucking problem. HDTs exhibit the least amount of chucking, even with big fifths
for two reasons. Typical HDT will weigh more or close to the fifth it pulls (even the "big ones") and second typical HDT conversion places the hitch behind the rear axle.
Which means that whatever motion is generated between the fifth and the truck gets dissipated behind the rear axle and into the rear axle, very little of it transitions forward into the cab area.