I'm not sure I've heard of Starnet blocking on AC. It's possible, but is usually reserved for the longhaul stuff, I thought.

If you stick with your original cnx, note that if YOW is anything like YYZ, they usually (at least, they used to usually) have an AC staff person somewhere in the line, who often calls out for people on specific flights closer to departure time (maybe 30-45 mins) and bringing them to the front of the pre-clearance line if there's a relatively sizeable line. That's my experience, anyway.