Thank you for your contributions. So what I hear is that it is standard Asiana practice to withhold at least half of the seats until check-in, right?

Does the OLCI's 48 hour time window apply to the first leg or to each individual leg of my trip? My first leg is MNL-ICN, followed by ICN-LHR. When does my OLCI for the London flight start? At departure time for MNL-ICN minus 48 hours or at departure time for ICN-LHR minus 48 hours?