Within Chat, there appears to be no way to select all of the text to copy to the clipboard, nor print the chat to PDF or printer. There is also no way to select more than about one screen of text at a time, because of the way Teams only keeps a small part of the chat in memory and when scrolling up while selecting it will reset the selection when it loads more of the content from the server. So in order to copy text spanning more than one page out of a chat I have to do it a page at a time, then stitch those sections together in an editor, including editing out the binary components that make up the More Options, Save This Message, Like This Message icons that show up for every line.

This applies to the Teams web and desktop clients. I found many other similar ideas already posted including duplicates but they weren't worded great and without the ability to search the ideas properly this site was returning a lot of results that did not apply so I thought it best to post this. Thanks.