I did a little research on it after I got back from my practice time with Chris. The owner's manual for the Soul in the US states that towing isn't recommended. However, everywhere else it's encouraged
I ended up finding posts by a dude that has the same as mine (2016 base model 6 speed manual). He found that being conservative with the numbers, it could tow an unbraked trailer up to a little over 1,200 lbs. The only issue I seemed to run into was the class 1 hitch requirement because all of the nice, affordable single bike trailers are for class 2 or above. I thought, no big deal, but then I read that they make it to where you can't get around that to use them with a class 1.
So....a Kendon single bike trailer ended up on my wish list. Their website recommends a class 2 or above, but states that customers have successfully used a class 1