I have a homemade pico console and I have an autoboot script to auto play games with and exe file. I have a script as well that runs p8 and p8.png files but it had some issues with multicarts so I just kept the exe file ones. If it's too much by all means I understand, I have no idea on how the process works. The only thing I saw was to export it as a .bin file. But I know Nerdy Teachers and a few others have done it so they could be of some help.
But overall all this rambling just to say I'd love to put this on a physical SD card to play on my console :D