Started looking into more storage options with 2 kiddies needing space. A molle panel would be awesome, but I had these bicycle pannier from my touring day. Just used some zipties to get them on.
Still pricey, but quality bags that's been collecting dust for over 5 years. Luckily I had a pair.
You can see the tip of my youngest's shoe, enough leg room for kids.
Flap opens to reveal the main pocket, good for jackets and spare clothes
Zipped front pocket and a elastic meshed side pocket (closer to door as they are L/R specific for your heal strike when riding), good for sunglass/sunblock)
The nylon straps allow me to tighten everything to be more compressed.