I have a piece of E-Track on each side of the bed wall about half way up in my trailer. My builder used them to help secure the fender’s bolts on the inside. And I have my chuck box strapped to one side and a table strapped to the other side. Then I pack everything else nice and tight. Once everything is packed it’s so tight the chuck box and table probably wouldn’t move even if not strapped.
I remember seeing this picture from the “Chaser #15 for Sale” thread and I was intrigued with the way it was packed.