if you open your F3 in gamemode 3 and enter an entity, your coords on x,y,z WILL change. but the facing (West, Towards Negative X)
will not change depending your facing
(tested in minecart)
see attachment for more info

• first pic facing west
• sec pic facing south (west is at the right -->)
• third pic facing north (<-- west is at the left)

still giving (West, Towards Negative X)