Xplane mission planner datarefs

I am using mission planner to fly my helicopter in the xplane and it flies great. But, I have some questions which are as follows,

  1. Xplane data can be extracted using datarefs, for example,

‘sim/joystick/FC_roll’(https://www.usna.edu/Users/cs/taylor/studentResearch/xplane/datarefs.txt - listof all datarefs)

Now, when the mission planner is controlling the helicopter which of the datarefs are mapped to the mission planner control inputs to control the model helicopter. i am using a computer generated signal from matlab to do some tests while using the mission planner PIDS to hold the heli in hover, i would like to record the actual signal going into the xplane model, i.e., (signal generated by the matlab+pid signal controlling it)

  1. How do improve the data rate and frame rate ?
    right now it is running at

data rate:23-27 fps
frame rate:550-650 fps

thank you