I cocked mine in the tree on Friday. I forgot to cock it before climbing. My foot was secure in the loop and it was easy. For full disclosure, my limb bolts are turned out 2 turns each for about 125lb draw weight.Can't you just stick your foot out in the stirrup while sitting in your JX3 and pull back? I cocked my mini that way although without the JX3. Leg out.
Edit : If your toes barely fit maybe not a good idea. Smaller boots?