I'm currently developing a handheld Pico-8 console using a Raspberry Pi Zero 2W, with a 480x480 HDMI screen for display. The system is functioning well, except for one issue: the Pico-8 screen does not scale to the full screen size. Instead, it is confined to a smaller square in the center of the display. This problem does not occur in Raspbian, where the desktop utilizes the entire screen area correctly. I have experimented with various resolutions, but there has been no improvement. Additionally, it appears that there is no config.txt file for the Raspberry Pi version of Pico-8. Could you provide assistance with resolving this issue?

You could try disabling pixel perfect mode (not sure how - maybe in the config file), but it will make it look ugly, with pixels of different sizes, so I recommend leaving it as it is currently, no way around it.

I think you can also specify if Pico-8 boots up in window or fullscreen mode in the config file.