I decided against building the slots. I didn't want to give up one inch of space, this box gets loaded! I did however upgrade from cardboard to wood. I had some thin wood sitting around the house, maybe 1/4" thick something. I cut it for dividers and taped them in like I used to do the cardboard. This trip we are taking the kitchen and dry food in the box. I even had a divided go perpendicular for holding up pans on their side. Now it is packed but I'll take a photo on the river.
I am a river, babe - I've got plenty of time, I don't know where I'm going, I'm just following the lines..... - "We are water" by Shaye