I'd never expect the check-in agent to do this. I'm not sure they even have the ability to do it? But when a full flight is edited 'in the back room' to try and move pax around, of course the status comes in to play. It's been confirmed on here many times by people with inside knowledge. Of course there are always exceptions and always anomolies which are very nice for the person involved...like The Hippy(TM)

I was on an (supposedly) 100%+ full flight to NRT last week in all cabins. I OLCId T-24 (Seq 001) and arrived at LHR very early (I wanted to get there a bit early to work in the lounge, but for various reasons ended up getting there almost 3:30 before and they double-checked if it was too soon to take my case!). At Zone R, I asked if I could be moved from 20D (4-block of W) to a 2-block of W near the front. I was told it was unlikely, but they'd make a note in my PNR. By the time I got to the gate and the machine spat out my BP, I glanced at the screen and saw I'd gone 20D-17K (^^ for them actually being able to fulfil my request!), then 17K->64K (as OpUps go and W-F aside, this would be my dream one ) then 64K-14K and then finally 14K-12K. So there was a significant amount of back room shuffling going on there!

I'd even shaved that day so didn't look like a SFU (Spiritual Flyer Upgrade?) hippy I did feel a significant amount of good karma after I boarded though

Phil