do they have any set ways they can do recon on this stuff or is it on them to sort it
from what i've seen, the blacksite has some big paranormal / supernatural / evil power to it, yeah? just let the rebels work with vortigaunts or something (maybe even get event team to play as natives to the region) and try to harness the power too, steal it from the union
this way it gives the rebels agency and something to do, so they can directly fuck over the union side, which will also keep the UU side busy since they'll have to fight the rebels
could even make it so the weird vooodoo power shit is connected to something tangible that both sides can defend, throw in some transmitters, explain them as what is controlling the weird shit in the area, let people fight over that and make bases around said transmitters, or even just have rebels try to repair some old broken one and get some good stardew valley type shit