Always interesting to hear other experiences and procedures. Moving pax for trim purpose on wide body? Normally the other way around in my experience, both as passenger and agent. Some lucky souls from the back have to be kicked up front. Being bumped after seat assigned? Here, once cut off is reached and wait list cleared, thats it. Anyone turning up after no matter how much huffing and puffing won't get on. Flight closed. Has to be really very extraordinary circumstances