Quick question: What is the bottom potentiometer on the back of the transmitter for? I know the top one can be used to control the pitch of an aftermarket gimbal but I'm curious as to what the other one does. While I was installing my gimbal I accidentally moved it instead of the top one. I put it back to where it was visually but I understand that these pots are sensitive enough to be a little wrong even when it appears to be correct. Also, if it's wrong now, can I use the software to set it correctly? Thanks!