No, there's no easy way to get tempos exported as text; you'd have to OCR a screenshot of the tempo list. But the easier way to get average tempos is just to get the start and end times of the section in both beats and absolute time and calculate beats/minute.
If you do end up doing it externally, keep in mind that you can't just average tempos directly; you have to calculate the absolute run time in minutes for the number of beats that each tempo pertains, and then calculate the average as total beats/ total minutes.