Well, changing flights can give you additional headaches in this area, so proceed with caution. If the flights are a long way off then I would not be overmothering the booking, just leave it to about 2 weeks to departure since a lot can change. But the key aspect is whether on the BA App, after refreshing the cache, you have a 125 number in the My Flights panel. If you have a number then do nothing until OLCI but check in soon after OLCI opens. If you can't get a boarding pass, at the moment it depends on the destination due to all the rules currenrly in place, I can't give a simple rule for that one. If you don't have a ticket number beginning 125 and you are in the 24 hour period leading to OLCI (48 hours from departure) then call up.