: I really wanted to try this day 1, but I can't figure out this steam workshop
: stuff. can you upload it to simplici7y?
It's really easy. You click subscribe in the mod's workshop page and it is automatically downloaded to your copies of Marathon for steam. Other games handle workshop content different but Classic Marathon allows you to select any specific WAD upon loading Marathon Infinity (but only that one) ala GZ Doom or Doom 1+2 Remastered, so you can load what you want it simply by booting the game.
Beware that your Settings used by the main trilogy don't carry over or at least they seem not to. I just got burned by that when I loaded the new version of Marathon 2 Special Edition to test the WAD loader.
(And yes, I'm using the Tomb Raider term for merged maps also used by Doom because many other players use that term as shorthand and "scenario" or "SceA" has always sounded stupid, like it's a Rollercoaster Tycoon level)