When Spencer got his first opportunity in Toronto it came due to injury at the slotback position. By the time he got to Ottawa he was eager to learn better route running and body control to make himself a more complete player. That gained versatilty let them utilize him in multiple situations. So in CFL terms I wouldn't really label him at a set WR position because he did both at one time or another.
For his size he wins contested catches pretty well. He has 4.3 speed and has a knack for working through traffic. How nice would it be to see a guy that can line up in the slot and still become a vertical threat on the play. Put this guy in motion and have Ben deliver a quick strike and he will turn that corner better than anyone on the team. Check out some of his back of the endzone snags and you may wonder how he is even able to track the ball in. He isn't as fast as Tyreek Hill but he isn't a headcase either. Fitchner would have a lot of options open to him with this little dude on the field.
You are so right about Duron Carter. Almost 6'5" and 205 lbs mom a sprinter, dad Chris Carter WR but an absolute dick on the field and even in the filmroom from what I have heard.
Solid analysis. If even close he will get a real chance to win a spot. I like a trier like Rogers and Switzer as much as anyone. But 4.3 speed. That is pretty hard to pass up.