...yeah, I believe it's long been established I have very little idea what I'm doing, so let's just have fun with it and see what comes about!
Honestly, I think it's clever to have Peridot's explanation of the Cluster happen because they had no idea how to actually move the plot forward.
Easy way to move it forward.
Have the earth shake, indicating it's "Happening" and then have them scramble to make the machine.
I mean, it's still pretty much powered by the plot, but there's a bit of that in all stories like this.