I found this website which for anyone who wants to add special fonts to Adafruit_GFX based display driver supported displays might come in handy.
http://oleddisplay.squix.ch/#/home
Set the Preview Display to TFT and the Library version to Adafruit GFX Font and then experiment. Once you have what you want then pressing the create button outputs the .h font file that can be copied and pasted as a new file under the src folder for Adafruit_GFX_RK in workbench, #include “name.h” and then display.setFont(&name); to use.
2 Likes