Hopefully GS mini is cleared up now, it shouldn't be an issue inside outside 4 dme since selected speed should be flown.
120.4, I've noticed your frustrations frequently refer to a slow down at 6 miles. I think this is because many operators select the gear down at 6/2000. Pilots flying manual thrust will anticipate the extra drag of the gear and add a handful of power to maintain the speed. Autothrust however will not add power until it seesa reduction in speed, and will after spool up give an unnecesarily large boot of power to return to the target speed. This may take 10 seconds or so, but if your mode S updates during this period, you will see less than 160kts at 6 miles. The distance lost in this scenario could be measured in metres, I would suggest.
Bare in mind that BA Airbus pilots are forbidden to use manual thrust because of the deranged musings of a discredited shed fur brains, and so you will often see this 'gear dip' on a Speedbus approach.