I moved up to an earlier flight, which meant giving up my FC seat on a connecting flight. This was at the ticket counter as I was about to check my 3 bags (no fee for up to 3 with FC, but no longer for Plats and below since the merger). They gave me tickets for the early flight, but tried to get $150 out of me for the 3rd bag since I no longer had a FC seat along with FC baggage rights. I asked for my original FC seat back, since thats a huge hit that I cannot afford. I was grateful that they were able to get my original seat back.

But it seems kind of silly to me. I wonder if there might have been some other way of doing this. Could I have checked in for the original flight and then asked to move up? Is there a window where rerouting my bags to an earlier flight is doable (and reliable)?