Only thing really not protected is drawing off the screen. It is pretty compressed so not that readable, but I'll post below in case someone would like to copy/paste and play around with it. It just uses the DrawHorizontal and DrawVertical line functions of the TFT library and offers 10 sizes in any foreground or background color with sign and zero blanking up to 10 digits or 9 with - sign. Maybe there is something like this already available, but I could not find it.
This worked well on a UNO with a Version 1 Seeduino TFT. Plus really large numbers did not look very nice. The draw string function was really slow and I needed to update several numbers in real-time on the same display without always clearing the background, etc.
Hey, New to the Arduino forum but thought I would share a short routine to draw 7-segment formatted numbers.