I use the extended x-chocks with my 246rks. No issues and they do a pretty good job stabilizing the trailer along with the scissor jacks on the 4 corners of the trailer. I have more than enough left over to create the needed tension. My trailer is a 2014 so maybe newer ones are spaced farther apart?
When I use them, I either wait for the tires to cool before I install or I go out later and tighten them. I have to tighten my scissor jacks after a day or two as well.
2015 F150 XLT Sport 4WD 3.5L EB
2014 Freedom Express 246RKS