Hey OP, I went to a SMP and am currently attending a US DO school. I think the worth of SMP really varies on if you plan to apply to US or Canadian med school afterwards...If you only want to apply to Canadian schools, then no, don't do a SMP and do some post-bach or 2nd bachelor in a Canadian institution. If however, you want to give US a try, then I'd say sure, go for SMP. Most of the SMP give you some perks when you apply for their medical school, and it also increases your chance of getting accepted in the US.
For SMP themselves though, I believe a vast majority of them are Canadian friendly, they are quite easy to get into. Pick one that offers the best perk for medical school application.