Does a compact folding luggage cart used to move around a carry-on bag or personal item count as an extra carry-on bag or extra personal item? Or does it count as part of the carry-on bag or personal item it is carrying, and subsequently doesn't incur any additional fee?
This depends on the airline for example Xiamen Air in China do not count foldable luggage carts as extra carry on and happily lets it come in board without issues.
However I tried the same on Air China and had to check it.
So best check the rules on the airline in question