Actually, I got my Pi connected to CRT TV, and you know how low res that can be, I saw ultibo, and it needs Hi res TV Monitor..
Ultibo does not need high res HDMI monitors.
Just a few weeks ago I plugged a 4.3" 480x278 rear view camera monitor into a Pi running Ultibo.
Without changing any settings it just worked, that was the first time I plugged a Pi into a TV RCA monitor.
https://ultibo.org/forum/viewtopic.php? ... view#p2226
It seems start.elf is now smart enough to detect when monitor or tv or nothing is plugged in.
It defaults to 640x480 when nothing is plugged in, I took screenshots without a screen.
Just for fun, I setup config.txt for a 4K screen and got 4K screenshots from the frame buffer with nothing plugged in.
You can configure the framebuffer for 1920x1080 and then plug it into a different res monitor, if the monitor is smart enough it will scale.
https://ultibo.org/forum/viewtopic.php? ... t&start=20
Screens down to 2.2" TFT 320x240 have been tested.
Plus there is font support for most types.
One thing I noticed about the piCore desktop is for the same res monitor is there just looks like there is more space compared to Raspbian.