[doofus]

Looking at this code you have posted:

function CompactUnitFrame_UpdateHealth(frame)
	local health = UnitHealth(frame.displayedUnit);
	if ( frame.optionTable.smoothHealthUpdates ) then
		if ( frame.newUnit ) then
			frame.healthBar:ResetSmoothedValue(health);
			frame.newUnit = false;
		else
			frame.healthBar:SetSmoothedValue(health);
		end
	else
		PixelUtil.SetStatusBarValue(frame.healthBar, health);
	end
end

It seems the "frame" has some "smoothHealthUpdates" functionality (how is that even determined?), but the actual health value comes from "local health = UnitHealth(frame.displayedUnit);"

So he is calling the same function as I am. I only can suspect that addons have lower priority and UnitHealth behaves differently depending on who the caller is ?