Wait, "snug cinches" is the part people get wrong. The zip tie shouldn't be snug around the bundle, it should be loose enough that the cables can slide a little. If you crank it down tight you can still pinch the cable and mess up the signal...

That ranger telling you the stairs would wreck your knees on day one was speaking from watching a hundred people do exactly what you did. Wet granite steps plus a heavy pack means every step down is your knee absorbing all that weight, and going up is no picnic either when the steps are tall and slick. Next time take the JMT up and save the Mist Trail for a day hike with a light pack, your knees will thank you and you still get the views from the top.

Same thing happens with kids and sleep schedules.