I've not deliberately tested either of those, but on group rides where that has happened, it's been a nightmare trying to get everyone back in group and not separated by the same distance. Freewheeling means 0 watts, and I think that then means that the scaling they apply to different powers ends up being x*0w = 0W and that stuffs stuff up.

If you all stop at same time for same duration. And on descent just fractionally turn pedals, all should be fine.