Rear Ported Speaker and Front Stage Question

I’m in the process of re doing parts of my front stage. The main speakers are in front and right up against the stage. I’m building a faux wall with like big acoustic panels. 1x2 frame wrapped in fabric. I’m curious if there’s anything I should be looking to do to help the sound. Like should I put Insulation inside the panels or leave them open. One side will have nothing behind the panel. The wall is probably 3 feet behind it. On the other side the wall is like 2-3 inches behind the panel. If any suggestions, please let me know.