I will be connecting through SFO arriving on AC and will have about 1 hour 40 min before my departing flight on Qantas to SYD. I'm concerned that if I have one of those OLCI issues that doesn't let me complete the check in I will have to leave the secured side and go through the regular check in process with not much time to spare.

Is there a way to check in airside? I will only have a carry on.

this is also assuming that AC won't be able to check me in through to SYD. Though I don't know if they can.