I finally got a party together for this! A few of my players were wondering if it was possible to use this to play a Fantasy Mech game? I've never looked at Lancer so I'm not sure if that's an easy thing to merge with
Certainly! You can definitely reflavor jobs as mechs, and the example Gigan reflection even mentions mechs. However, if your group are interested in doing fantasy mecha, it might be worth seeing if Lancer can slot it in easier. Either Lancer or Beacon will require some reflavoring, but depending on your tastes, one might be a better foundation.
Either way, both are great games! If you want to get more opinions, I'd recommend either games' discord communities. I'd be surprised if the question hasn't be raised in PilotNet (Lancer's Discord) before.