I am not going to lie. That sound like a bad idea.
The FLIR Duo Pro is not a supported camera so you will have to deal with triggering on your own.
The best thing you can do is save a mission that covers the whole area you are going to be covering so you will have the basemap and terrain info for it. From there you can do what you need to do in the field. Make sure you can connect to the aircraft and everything before leaving an internet connection and use the simulator to make sure things are working properly.
The process is exactly the same as it was before.