I hope it is the real reason, but I just feel there might has hidden reason.
PACE works fine actually. I donīt understand why you think it does not. "The others" only are looking for a pace which is more sensitive when changing running speed. But the problem is still and ever sensivity versus accuracy
And itīs also clear, that PACE is shown to fast, when distance which is measured by watch is longer than in real.
The to long distance comes from the snakeline instead of a straight trackline. But this topic is "GPS-accuracy" and accordingly "different distances GH-505/GH-625". I will write some more in the distance-topic.