Unfamiliar with it, but in the regard of instances going down, specially after my previous main instance died with no signs of returning (again), if you find any interesting posts even on instances seemingly stable, I think it is a good idea to back up those pages. Personally, I would propose methods like Internet Archive's Wayback Machine and its alternatives like Archive Today, the print to PDF option from browsers, and/or saving a given page as a MHTML bundle.