Maturity Is a Lagging Indicator. Here's a Leading One.
A maturity score answers where a program has been. It reports the state of documented process at the moment somebody assessed it, on a cadence measured in quarters or years, using a scale that describes organization rather than outcome. Every property that makes it useful for planning makes it useless as an early warning. The interesting question is what a leading indicator would look like instead, and the answer requires separating two problems that get treated as one.