I heard a famous podcaster state that he had "read a study" that yeast express 30% more esters when rapidly chilled. Like many, I took what he said as fact even though he didn't actually reference the study. Its kind of an EF Hutton thing. I switched from one-step rapid cold crashing to slowly lowering the temp. Now days I have gone back to the one-step rapid cold crash.
I have a theory which ive picked up along the way and its been reinforced by sour beer brewing. The hydrometer tells us one thing about our beer. But we also should taste and look. If your beer has reached terminal gravity, AND it tastes done, AND it is at least starting to look done (no foam on the surface and not full of yeast in suspension) then rapidly cold crashing makes little to no difference. If the yeast are still busy, it might make a difference. So why not give them (for example) 9 more days to finish up at a temp they thrive in then crash in 1 day, rather than slowly crashing by 3 degrees per day for 10 days?
I only have one fermentation freezer so I can't do a side by side, but ive got enough experience to know which one to bet on...
If you brewed two identical beers side by side, at day 14 you ramp to a D Rest, and at day 16 you started slowly dropping the temp of one beer a few degrees per day till it hit 30F on day 28, but let the other beer sit at that D Rest until day 27 then rapidly crashed it to 30F overnight... my money is on either no difference or the rapidly chilled beer being better. (This is an analogy, I don't brew by a calendar)