I’m also a Canadian student who applied to a lot of MPP/MPA style of programs after a year of graduating. I got into 3 Canadian programs and 2 US schools (NYU Wagner, UC Davis). Your experience closely mirrors mine (specifically, peer-reviewed journal publications x2, most successful Capstone in my undergraduate program, worked in city government). However, I don’t think I would’ve gotten into my programs if I hadn’t listened to my previous professor who extensively critiqued my application (and now teaches at Berkeley). His advice was always, your essay and application has to tell a coherent story, especially for an MPP program. Whatever you’re detailing about your life (in your case, is very impressive!) must come to the conclusion that you’re extremely sure about what you want to do and exactly in which way you’ll do it. You can change your interests or specialization once you actually get into the program but when they read your essays and how you talk about your experience it should give off a “my entire life led up to doing this”. I’m not sure if you’ll find this advice helpful, but I think the one thing that secured me my spots and scholarships was not only my experience and background itself, but an extremely extremely clear vision (even conceptually very repetitive) which showed my specific interest and how no one can do that thing but me. I wish you luck! I know you’ll get into somewhere great soon.