Joking aside, it's quite noticeable how much she's facing downwards when I carry her on my front with a heavy load on my back,due to me leaning forward. Wonder what thatll do to my posture long term.
Unless you’re carrying heavy pads several hours every day, the driving to the crag is probably more detrimental to your posture!
Though sitting in a car seat is far more movement constrained/controlled - so it’s quite hard to jar the back/bend it in an odd way - which is quite do-able with a teetering pad combo....
But moving on from a rather minor point above (I wasn’t sure if you were being facetious or serious there TS 😃) - taking a load on the hips is really important to help back strain.
On a backpack that’s far easier as the load is typically more compact and you can put all the heavy stuff at the bottom. So much so that with a well packed backpack you can almost have the shoulder straps loose as the weight is square on the hips.
With a large pad combo - the weight sits far higher up closer to the shoulders than hips - so whilst hip belts take some strain and some of the load - you still have to lean forward and take a load on the shoulders. I kinda wish pad designers would allow the hip belt to therefore sit higher up the pad (then it clouts the back of your thighs I guess)