Good points.
“One thing I think people get wrong when we try to copy fish anatomy is that fish flex their bodies and constantly change the shape and stiffness of their fins. We don’t have that ability with rigid parts.”
^ dug this – seems an obvious point to make, but yet is seldom made.
Out-effing-standing…I rely on these boxes – please never stop making them! IMO if you could make a version that are easier to cap, or that come with a built in cap like an FCS leash plug, and maybe a quicker install system, they would compete with FCS/Futures for market share.
Probably it has all been said before, but IMO the only reason these are not getting that kind of market share is the install process (time required) and what has to take place for a functionally dependable install. I use the tape-off-first method I first saw on this site (you may have been the one that posted it, I think, PL), installing over the lam, and then hotcoating over the edges of the boxes – others seem to be able to get a water-tight results without that last step, but I’ve never been able to, consistently. That means, at least for me, maybe due to limited experience/expertise, that I have to be present to pull the tape off under the hotcoat at the right time.
Unsolicited request/input, but had to take advantage of the opportunity since the company owner may see it. 
I gave away all the Probox stuff I had to my buddy John up in Newberg. Quite a few boxes, inserts, install kits etc. I haven’t seen any for sale since. I’m actually surprised to see Lokbox still for sale once in awhile. I thought they were gone.