setFontCustom bitmap format vs vertical_byte:true - GT24L24A2Y fontchip in F07 fitness tracker

Ahh - I think this is what you need - this code creates the font in Graphics directly: https://github.com/espruino/EspruinoDocs/blob/master/modules/Font5x7Numeric7Seg.js

var gr = Graphics.createArrayBuffer(H,digits.length*W+2,1,{msb:true});
gr.setRotation(3,1);
//...
var font = gr.asImage().buffer;
var widths = E.toString(widths);
g.setFontCustom(font, 46, widths, H);

If there's somewhere you think I can improve the docs around setFontCustom let me know though - I know it's not great.

I guess there's the possibility that something that renders direct from flash could be built into Graphics, or that setFontCustom could have extra options?