I find that loosening the trachea and esophagus as far inside as possible from the neck end makes dragging all the guts out the back end much easier...still ain't easy, the older the bird the harder it is to do. I rarely get the lungs out until final rinse and butcher, I chill the whole carcass in salted ice water and cut up later to portion in freezer bags. I still rest before freezing, even if I'm going to stew, it makes a difference to me.but my initial question was how to make it easier to eviscerate, as that is the hardest thing for me to do when keeping the chicken whole.
I would be paranoid about cutting back out before removing intestines, have never broken a bile sac.