Leviathan Frame or Consignment of Scintillack Snuff easier to get?

I'm building the track to Jericho Locks and have cleared the work stoppage. Building track gives me cool items now depending on how I approach Furnace, but I'm assuming it's only for this station (?). The first one I did was the one that got me Mutersalt because it's apparently otherwise Fate locked, and since each station needs 3 sections of track built, that means I only have one more left (I think?), so I'd like to use this opportunity to grab whichever item is harder to acquire.