I have a 36 hour day coming up involving two different UA tickets, and I'll have to leave home more than 24 hours before the start of the 2nd ticket, so can't checkin at home for both records at once. Can I use an EZ checkin at one of my intermediate airport stops to checkin for the segments that begin elsewhere? For example, will a machine airside at LAX let me checkin for a separate ticket SEA-ANC-SEA if it's less than 24 hours out?