this feature probably hasn’t had much actual testing yet 
I’m guessing you will want think of this as “layers” and the png will probably be a background, so you’d load that first then add text next. Not actually sure what to expect if that’s being called a bunch of times in a row from a redraw() on a metro.
I’d check to see if your redraw() has everything in the same order as the init()?
Also - think about optimizing the image for the size you want it to be on the display, reducing colors, etc. (try to keep the file size small)