Hi,
when I was testing your library on Atmega 328 (VGAX), everything was fine.
But testing it on ESP-07, not NodeMCU, i've changed pins from D7, D2 etc. to GPIO pins (just 13, 5 etc.)
Compilator was giving an error, "D13 is not defined"
I think you should make 2 versions of library, of define board type in vga.begin(board);
Non-advanced users won't know wheres problem.

Anyway, I'm writing an tutorial with using your library :)