DrS has mentioned a few times fermenting warm with this yeast to push the esters (I do the same thing. Those stonefruit esters in 1469 are
choice.)
If you do brew >20c, you need to be careful....the warmer the ferment, the faster it will go; the faster it ferments, the more heat it produces; the more heat it produces, the bigger the difference between ferment temperature and ambient; and the more heat it produces, the faster it goes, bringing it full circle in a vicious cycle that can get away from you if you're not careful. Normally you would expect a degree or 2 different between ferment temp and ambient....I've had 1469 up to 6C over ambient, because it was racing so much. So whilst fermenting at 21 or even 22C is fine for this yeast, just be careful that it doesn't race away from you.
(if you use a fridgemate and have the thermo on the actual fermenter itself, instead of just reading the ambient in the fridge, it will take care of itself and prevent this. I don't have such luxuries...)