What I've been doing when people here post Mastodon links to is add .rss after the @whatever bit which lets me grab their RSS feed and then I can scroll through that to try to find the post being mentioned. I'm not sure the entire post always shows up, and I think you don't get replies or comments or whatever Mastodon is supposed to have with posts, but you can at least get some kind of information out of Mastodon that way.