I couldn't find archives of Exo's spliced speedruns anywhere, and I was wondering if they were just gone forever.

sorry for the very late reply, but no! if you have a link to the original 18:45 any% Youtube video you can put it into the Wayback machine for an archived version. i dont have a link, but an old gamefaqs forum should have it IIRC

archived versions of speedrun.com/smb may also have it

i have the entire 18:45 run downloaded to my phone though. i can upload it somewhere and get back to you

Please don't rehost someone's runs when they seemingly don't want them publicly available, thanks