Towing? Never. There is a lot of info on the board about towing and other overspeed methods. As a general consensus, most choose not to do it. If you do decide to do it, downhill running on a very low decline(1-4deg) is probably your best option.
In my opinion, I think implementing it during preseason is a bad idea. I see it more as a peaking method. I would say using it for two weeks(2-3 workouts total)in conjuction with traditional maxV methods, then allow two weeks to adapt and compensate. So in short use it a month out of a champ meet.
That’s my take. Search the board, Im sure you’ll find more than a few threads on the positives and negatives as well as experiences.