I am a fixed-wing pilot. I fly full-sized airplanes (Piper Cherokee, etc). I am used to moving the stick backward to pitch up. This is opposite to the pitch control on my new Mini 2.
What mod(s) are available to me to reverse the Mini 2 pitch control?

Check page 30 of the manual.
Those options are available (3 modes)
To my best knowledge you cant reverse them.

Hi PhotonMuse, you may refer to Montfrooij's reply on 2#, you can customize the stick control on Control Settings. Hope this helps with your request.