There are no ban waves...if you use bot incorrectly you will get ban within 1-2 days if you use pokesniping same and so on! Just be smart and bot safe!
I have collected on 10 gyms at once with my main account that got banned.... Guess what that account it back up and working. I was using Jailbreak mostly and taking every gym in my area. One day I'll take 10, few would be left over so I would try and take another 10 etc. I was getting close to 100 coins and 5k stardust a time.
Indeed there is risk but i am lucky and i bot with safe settings and follow the messages/stop times of the bot and i think so far we are not in big danger.
I have 3 accounts opened around a week ago. Ranging between levels 24 and 27. no teleporting. All in the same (major US city). I rotate through them (only running one instance of the bot at a time), switching every 100-300 pokemon caught. I have it set at walking speed and stopping randomly at stops. As far as I know (from watching the feed), never had even a minor soft ban on these accounts.
I always override the Pokefarmer auto-kill switch as i'm switching accounts.