I haven't used any lube on our 2014 yet though bees wax noted above might work if you feel that it's needed. The cables don't slide anywhere(or shouldn't) so little need for lube, The chain is factory prelubed. A petroleum product might drip on the slide roof and damage the EPDM .
If it's a rattling, creaking or jingling noises that you are concerned with, then you need to do cable adjustments.
Traveling with my DW Susan, a couple poodlepups and our 2014 Montana High Country 343RL, being towed by a 6.7 2011 F250 CCLB using a B&W hitch and OEM puck system