I'm aware there are some limits to its use, but I don't know what they are. I have used sprintf with Arduino successfully so, whatever the limits are I am yet to come up against them. However, @JohnRob commented that he didn't think he could use sprintf with and OLED, not that he couldn't use it with an Arduino. My point is that providing the limits on using it with Arduino don't apply then it is perfectly possible to use it with an OLED in the way I suggested.