Gregg, I'm reading through all this trying to come up with a solution. Now I just get to thinking if you're not over thinking things. Reason I say this is, you said it's a 150ct humidor, and you have a CO and 4 hygrometers in there? I don't say this as a rip by any means, but is there a chance with that many hygrometers (and we all know that hygrometers vary) that you just have too much information and it's all getting confusing? Just thinking out loud here. Get a bunch of beads and give them a try, remembering that with beads, surface are is paramount. You can have 2lbs of beads in that humidor, but if they're in a container with a small surface area, they will be less effective than 1lb of beads that are spread out with more surface are.
Again, just thinking out loud here.