I once was able to use my browser's find tool to identify a line from a chat. Then Gmail introduced lazy-loading to chat history, and that became harder; my workaround was to click Print and then use find. But Gmail just recently did away with the print button, and I can't even do that.
Gmail team: the UX is worse; users are loading _text_, and usually not much, so why lazy-load every few lines? I understand I represent an outside use case, but I don't see that the new chat history is more inclusive in the use cases it addresses.