You can get the full list of modes from the micropython docs. https://github.com/pimoroni/picovision/blob/main/docs/hardware.md
I first wrote this in C++ and the Pirate overlords liked it and wanted to include with the the shiping firmare.
But the examples are all in micropython, so I created another version for that.
I create an list of screen resolutions plus a flag of 0 for normal modes or 1 for widescreen.
Using button A and X will move up and down the list and Y will select. After selection the PicoVision will stop the display and reset in the selected mode. There is a time out (just like on you PC) just incase your monitor cannot display the mode. Hoevery if you can see the mode change you can press Y again to confirm the selection.
If you are not using the WIDESCREEN buld of micropython, trying to select a WIDESCREEN mode will result in the selector turning that line RED and displaying 'unsupported Wide Only' message.