Can you time the LCD.printNumF() function ?
Yes. I was thinking about that last night. I will make up a programme for the purpose. Print ten lines. This was prompted by getting suss about the fonts.
This job uses the Henning Karlsen library and was derived from one of his examples.
he library has three fonts - small, large, and "SevenSeg". All the stuff in large font is fixed before the loop, but I'm getting very suss about the big 7-seg in the corner. The lines are 5 px thick and there are probably more pixels updated there than in the rest of the display, even though the dp is fixed. There is no dp in the font and the digits are printed individually, which probably doesn't help.
I experimented with printing strings to serial monitor long ago and found that floats won by a wide margin every time. I concluded that the only time one should ever use strings is when the receiving software demanded it - which is not often. I guess that was a bit hasty, and maybe there are times when the hardware is better suited to strings.