So far I've found the HA Corvette mission from Hack MD.....
https://hackmd.io/@Eldraen/SJd1_hBKL
And I've seen a recommendation that the Mech Hack: Mission Manual can be easily repurposed.
But I think we'll likely just have an NPC mech ambush an Everest PC mech as they transit a ravine, transporting some critical hardware/medicine/intelligence or similar.