Well put. Has the idea of a quality factor (Q) for a political "echo-chamber" been defined? Seems like an opportunity to inject some rigor into some commonly used terms.

One could measure the decay time of conspiracy theories through number of articles/posts published to determine the Q.

Or one could try to determine the bandwidth, as the allowed deviation from orthodoxy - a high Q chamber would have everyone parroting the exact same thing, whereas a low Q chamber would admit significant variability. Seems harder to quantify this measure though.

Also no reason to assume those two measures would be consistent. Needs a more rigorous approach to ensure self-consistency.