an open cone is only best used relocated at the front grill or bumper where it can get the cooler air, it will get heat soak if on or near the throttlebody, even if it has cool air ducting going to it as it doenst do enough in my opinion. you can get the shielded cones where the ducting is sealed/clamped on to the shield, a bit like a standard airbox really lol, but at least it frees your cool air inlet design a bit more.
but you can get very good customised standard type air boxes with better ducting setups.
i have used a larger uk 1.6 nissan standard airbox with larger bore ducting inlet, clamped to this is flexi ducting going straight to the front with no restrictions or chance for heat to get in.