My advice to all companies in the modular synthesis world: DO REGISTER YOUR FRONT PANEL DESIGN! This falls under copyright protection and it makes it very difficult for other companies to almost completely copy that. The FOUR PLAY module from Behringer looks a lot like the Quad VCA from Intellijel, and I'm certain that this will result in a copyright infringement if the design is registered!
Software and Hardware are almost impossible to secure in this way, but at least you can secure your look and feel!