Amusing thread. The words "when appropriate" came to mind.
I was trying to play something up to speed last night when my wife commented that I was going too fast, and so I thought I'd share.
It is the fastest thing I've ever tried to play and is correctly marked on the transcription as
"c.212 Swing 8ths". Yes 212 is off the metronome scale. Trust me, I wasn't going too fast.
The image below is a short section of it:

you can see there are five nice & easy bars of swing (big hands are useful cos it's only partly pedalled) before you hit bars six and seven of the image, the fast right hand run coming down from the high D with thirds fingered 4/2.
Over-practice initially of these two bars gave me mild RSI in my right forearm due I believe to lifting the fourth (& second) finger rapidly and repeatedly.
It may be the most difficult run of the piece to get up to speed, but it's not actually the fastest, there being a run of single notes in 5ths that is a near glissando at a speed of c.212.
I'd be interested to know if other people find that right hand run as tricky as I do?
Anyhow, after my wife's comment, when in company I'll be careful to play the piece at a speed appropriate to my ability that makes it sound musical.
Regards
Andy