I've noticed that for some reason many KSG shooters put their right arm under the gun, right where it'll get hit by ejected shells.
I early on learned when shooting a long gun the "triangle" hold of holding the right arm out to the side of the gun to form a supporting triangle for a steady hold.
In rifle shooting at least, everything is based on supporting triangles of both arms.
The right arm horizontal to the side of the gun, the left directly under the gun.
With the right arm out to the side, the shells don't hit your arm or hand.
This is a matter of how an individual holds a gun, but I don't understand putting your arm under the gun.
If a deflector is desired, smaller is better.
What you'd want is as small a device as possible that will allow unobstructed access to the loading area, but will still deflect the ejected shells.
It also needs to be as unobtrusive as possible, light in weight, and no bigger then absolutely necessary.
I'd think you could make your own from Kydex sheet and a heat gun.
I'd start out with something like the last one shown above by Primary Machine, then start cutting it down and shaping it until nothing is left except only what will do the job.
Most of the pictured deflectors appear to be much bigger then really needed.
Possibly all that is really necessary is a very narrow strip below the rear area of the receiver that will deflect the shell just enough.
It would probably be easiest to mount using the trigger group pins, but it would be necessary to insure that bumping the deflector won't pull the pins out.
Screws would work but that makes disassembly of the gun require tools.
Possibly something like the KNS pins used to mount a sling would work.
Once you have a good design, make a nicer looking version for actual use.
Again, smaller and simpler is better.
:trend:
