Hey all,
This is the project's current lead - we're not definitively switching over to Unity, but it is an engine we've discussed using in some capacity. It would have some advantages, but the obvious issue would be the time involved in rebuilding/importing everything, and some legal greyness, too.
I think what we're hoping to do is find a more updated FOnline SDK (made available by other game projects) and perhaps use Unity as a way to drag & drop assets for mapping. I am not sure how possible this is, but basically, we are exploring ways of streamlining our process since FOnline's tools are not always the most efficient.