I couldn't find an existing 3rd party tool for downloading your Private Mentions* to archive everything before my old instance goes down
(* none that'd preserve the entire thread and both sides of the conversation)
So I made a nicely formatted text log for the first set of PMs, which took forever
Then got lazy and just grabbed the raw html from the <div> containing the PMs column on the webview and did that for the other PMs I wanted to keep records of ^_^;