Stabilized Camera / Pan-Tilt
With a "two servo micro gimbal" you can tell iNav to stabilize your camera. The flight controller already has tilt sensors and a computer, so with the iNav software setup right it can control the servos and stabilize a camera. You do need to have 2 extra servo outputs on the flight controller.
There are a number of these on Amazon. If we just search Amazon for "servo gimbal Mini Pan-Tilt mount FPV" there are several for under $25 but you may have to put in your own servos.
You can also 3D print the plastic parts and add your own servos. This is for a Raspberry Pi or Jetson Nano type camera but should not be hard to get it to hold a DJI Camera.
There are also head trackers so that the airplane can point the camera where you turn your head. This increases the feeling of being on the airplane, so can increase the fun.