CX was always ok to hold your booking as long as a reason was provided to GO and SL, normally few days (if not too close to departure) is fine. However, that would involve a phone call to CX to hold and another phone call to make payment.

Now they're making 72 hours online holding for everyone, free to MPC members, which make it really easy for a MPC member to hold multiple possible itineraries and choose one to ticket later.