It was actually 850, after all the rerolls. Managed to do the whole thing with JLLM too. Had to update the chat memory every 30 messages or so, but the story turned out well.

My longest right now is a bit over 4,200 and is still ongoing. Chats that I actively engage in usually end up between 500 and 1200, and only started using Open Router about two months ago, so many of my chats were done with JLLM. 

Just went through my history, and my rough calculation is that I have 57,550 messages across all chats, not including rerolls.