Well I made it to the range and fired about 50 slugs throught it. The handguards worked well and had no issues. I haven't had a chance to start working on a new design yet, work keeps getting in the way 😢. I will post when I have a update.
Edit:
I haven't ordered a Unity Tactical Hot Button yet but looking at them online it looks like it would be very easy to add it to the handguard. I was thinking of maybe flush mounting it and having a cable channel. Could someone post a picture of the backside of the button straight on with a dime or penny sitting in the center of it so I can reference the size. The thickness of the plate would be helpful as well.