In the last decade or so, there's been a rather large change in what an exceptional espresso is.
Back then, mouthfeel was king; if the espresso wasn't an emulsion with a mouthfeel somewhere between molten fudge and a smoothie, it wasn't exceptional. Throw in a chocolate truffle taste, with a twist of alcoholic or berry ferment, and you had the complete god shot. A combo of the right Harar or Yemen, with a good Sumatra or PNG, a good Cerrado, and a dash of a high end Ugandan robusta, and you were home free. Of course, godshot Harars or Yemens only came around every few years or so. Between those times, you had slight misses that reminded you of the perfect ones. Cooling a shot like this would have been as insane as waiting for the souffle or zabaglione to collapse before eating it.
Now people are looking for espresso akin to the perfect brewed coffee, only with ten times the concentration. Cooling for this style shot is a good idea. In any case, the seductive emulsion shots are gone until this style falls out of favor. When that happens, we'll all need an entirely new set of expensive gear and secret tweaks.