I sold them a tray of live daikon radish microgreens and they haven't used it yet. They are still alive and even a week later, when harvested will be perfectly fresh. Simply swapping the water in the bottom tray once every two days is all they've had to do, placed near a window. This hasn't required any refrigeration at all. I think they are basically locked in stagnation because they're nutrient deprived, but have enough just to survive at this stage. As far as product shelf life goes, this is pretty amazing.
While that is one method some growers use, it's far from a settled debate and honestly seems more like "bro science" - which the cannabis community as a whole suffers from a lot (dont get me started on the indica vs sativa nonsense). In my personal experience I've grown using both methods and seen negligible differences between the two.