I've seen all three in use, and while agree that "maturity level" is not "absolute objective truth" - that's your overstated reading, but IMHO dismissing them a

I've seen all three in use, and while agree that "maturity level" is not "absolute objective truth" - that's your overstated reading, but IMHO dismissing them as mere "personal preference" is also wrong in the other direction. These are not personal - they are are the product of the interactions and agreements of a large number of co-operating people who look for ways to deal with release quality concerns with instruments that they are familiar with: signoffs, manual gates, controls; vs. automation and small batches. Also dismissing them as "mere preference" implies that the outcomes will be broadly similar, in my experience this is not at all so. The industry has uncovered ways to proceed both fast and safely, but these are not widespread, partly because of the myopia that they are mere "preferences".