When using a Spirit GT with a Geolink 2 six functions (in channel setup tab) is not enough to use every function of the Spirit and Geolink.
I'm not sure how many functions makes sense to the devs, but for my specific setup I need seven functions not six. I did get it all working by putting rescue on gyro gain, but to me that is not ideal. I would rather have a dedicated channel instead of using negative gyro gain for rescue. Much easier to set up and to understand, at least for me.