The door panels have always been on the car because I am trying to figure out what to do with the door handle before I can take them off. So to answer your question...my FX1 has about a 1/2 inch between the shoulder bolsters and the door panel. Do you have the FX1 or the FX1 Pro? I have the Pro. There is a 1.5" difference between the two. Here's the dimensions of the two...Could you hang the door panel back on for a minute and LMK if the FX1 touches the door. I put my CR1s in and they rubbed the door panels.
Sorry for the highjack
back on topic, I saved ~1 lb by removing the odd standoff brakets used to hold/clamp hoses nad what not and replaced them Adel clamps. Very tedious but looks better IMO.