There have been a lot of changes with the game since this was logged. Just wanted to run a few quick tests to see if we are still discussing the same thing as posted. As to the duplicates logged, this seems to be the only one showing numbers that can be objectively compared.
METHOD: Tested with Dev Branch (1.55.133793) only. All testing was done with the mission provided loadout while at rest. The only movement being the stance changes themselves. Each stance was held for 2 mins to allow for any settling.
CONCLUSION: From my testing it appears that the aiming deviation hasn't changed at all significantly over the intervening period. I don't think I'm qualified enough to draw anything further out of the numbers ;-)
Graph is here:
Raw Data (CSV) here:
EDITED: '~' seems to have a special meaning here. Removed them.