Last time I was checking a bag at YVR, a few weeks ago, the couple at the next check-in stand asked whether they could check their bags and then not proceed through customs right away.

They were told that there is a 15 minute timer that starts when the bags go down the chute - and the boarding pass is scanned until the next boarding pass scan checkpoint, which is at the entrance to security. If you take longer than 15 minutes to report to security, your bags get pulled aside and you get the equivalent of SSSS security screening - i.e., the third degree.

So don't plan on dropping bags after checkin and then wandering around land side unless you want to spend a lot of time getting frisked and grilled at each subsequent step of the process.

P.S. If you want a sit-down (not food court) lunch before checking in and don't feel like paying to check your bags in day storage, the best bet is the Fairmont hotel's restaurant right above the US departures concourse. Seond best bet is the Asian restaurant land side just before entrance to the International (not US) departures concourse.