Chord produce a cable-pack that includes a basic 'hollow' module, that reduces the possibility of stress being exerted on the plugs/sockets.
Please understand that I'm not trying to imply that you must buy another Chord product in order to get Mojo to function reliably. I am simply saying that Chord cannot control how much stress people apply to Mojos sockets, and using the basic module is one way both customers and Chord can ensure any such stresses are minimised.
However, you may do as you wish.
If you prefer not to obtain a module, then you may find some plugs fit a little tighter than others, but, fundamentally, no matter what cable you use, you will still need to ensure that stress is not applied to the plugs/sockets whilst your stack is in your bag or pocket. If you can't find a way to ensure that, then you may not experience a 100% reliable connection.
www.head-fi.org/t/784602/chord-mojo-the-official-thread-please-read-the-3rd-post/24300#post_12942830