The boards look like they are progressing. I know a lot of guys have already given you their feedback, I just wanted to add, coming from the aircraft industry, you can never do enough testing. Even when you think you have made it super strong, someone will break it and then it will be on you. Once you start producing or manufacturing something in a jig, if there are any weak points in the design every pair you produce will have that same weakness. That is the catch with manufacturing.
Just a thought that you may want to consider, is having your inner bar connect up with your outer bar, that way you create a "box" effect which ties everything together. (see picture for what I mean)
Also the factory bracket is a weak point, we dealt with it by eliminating it and doubling up the tunnel at that point, something you may want to consider thinking about at a later date. Always strive to continually make improvements and if you don't have the time to test the product properly, then just delay releasing it, trust me you will be happy you did!
Just my .02 Keep up the good work!