RATIONALE
Essentially, we're not assaulting into the tunnels until nightfall because we're bringing Reds with us.
And the Reds cant assemble in daytime. So we can use the time productively.
Sandra's chaos ritual was primarily enacted as a buff spell/mana manipulation ritual to prime the city with appropriate mojo, so whatever her magic plans are easier to enact, and to make the response of other people worse.
So taking it down will debuff whatever she's doing, and will make it easier for us to lead a force into the tunnels.
Also, directing a sudden, heavy cloudburst of rain on Las Vegas will dump floodwater into the tunnels.
Running water like this will thoroughly fuck most magic ritual preparations in those tunnels, and erode or damage magical defenses and alarms that the floodwaters can reach.
It will also provide enough water and justification for Molly to have BSM active when we go into them.
When we're done w, Molly can chill in some bleach water to regenerate Essence before nightfall.
Two hours will regenerate 8m.