As with many things in life practical experience trumps anything you can devise on paper. I love my Williams and Joseph Confluence chest pack for fly fishing, but it has a few weak functional design elements. I found the mesh divider to be inadequate, my items kept slipping underneath and onto the foam fly keeper deck. Next, I didn’t like the way I had to angle my hand and wrist to place and retrieve flies onto the foam. Also I think the gaps in the foam are unnecessary; maybe one row but not over the entire foam panel. Most of all I didn’t like the net holder cable which is placed in the middle of the back pack. This position made my net hang too low and also allowed it to slide from side-to-side. So I made a few hacks to improve functionality.
I also wish they would have used heavy duty zippers. I’m sure you can find a few improvements to these hacks. I recommend using a stainless grommet instead of brass. Also, it would be nice if the pack material was more waterproof, but I haven’t been able to solve that one yet.