I have an all weather commuter, equipped with 26x1.75 studded tires when necessary, slicks when not.
Last year I had three falls, really due to frozen tire ruts hidden beneath fresh snowfall. None produced injury, but any one of them could have inflicted damage on my 62 YO body.
I bought my son a Worksman trike this Summer, and am seriously considering fitting it with the studded tires for Winter workouts.
Having two, would you put one on the drive wheel and one on the front? That's my initial line of thought. The freewheel side rear does nothing but hold the trike up, after all.
Thanks for the thoughts.