I would like to know if the Vex transmitter is equipped with a trainer port/buddy port?
There is not a trainer port, but you can make one with code. There are 2 receiver ports on the Vex Controller. You could make port 1 be the master and port 2 be the trainer. Through your code you would check for an enable signal from port 1, the master transmitter. If the port 1 signal is detected then port 2 inputs would work as normal. If the signal from the master transmitter 1 or port 1 is not detected, then port 2 or the trainer inputs would be ignored. Code to support this function is left to the user to develop.