>>2452347>diaper bagsYou're talking about this? Didn't know it's called that. The one we have can be used to mount in the back of the stroller as well.
Bug Out Bags for kids are planned. Initially just a change of clothes, snacks and fav plushie. It will grow with kids but you can't really put any weight in it from my experience. 7-14 years olds would slow you down either if you carry all the weight from my experience. All will come together when we'll start mountain hiking