It gets VERY hot inside the cowl of planes like this. IMHO, placing the module BEHIND the firewall, away from some of that heat, is a ggod thing. A small hole through the firewall to pass the ingnition HT lead through, and another even smaller for the trigger, seal them w/ silicone. Mount the module to the back of the firewall. A small vent from the side or bottom of the fuselage to allow some air through the tank area to vent it and provide additional cooling for the module is a good thing (might also help avoid an explosion in the event of a fuel leak inside the tank area)...