This is what JBC's marketing claims: https://www.jbctools.com/top10.html

Though from looking at some of the chatter about it online, this is only one specific tip they make under ideal conditions, and it seems like often they overshoot the temperature by more than a little on warmup (though this will be the slowest to recover with the tip just held in air as opposed to when actually soldering). Either way, I've used similar products and this kind of speed isn't a crazy suggestion to me.