I was always taught (and in turn taught others) to trim any aircraft properly, at all times.
If a pilot is taught to routinely fly the aircraft out of trim, at any stage of flight, it seems obvious to me what might go wrong. Especially on final approach to an unfamiliar airfield in poor visibility, where some of the pilot's attention might get diverted away from the proper priority of poling the aircraft. If you're not flying the aircraft, it will fly you. You know where I'm going with this....