If you purchased your phone in the US, you will not be able to trade it in on the Canadian samsung site. The IMEI is not recognized. I also confirmed with support.
I would never trade it in you can make more $$$ privately
You would think but I priced it and for base s21 128gb it's giving me 625 credit (225+350+not sure what else) through SPC. Which seems pretty good but not sure I'll pull the trigger
I would have to sell it for 950cad here to come out the same. Possible but may be tough. The trade is hassle free when it works.