So it seems custom resolutions are not working at all in virtualbox.
No, that's not true. You need vboxmanage e.g. for wide screen resolutions. But apparently the maximum of pixels is limited to the amount of 1600*1200.
I found the following thread :
https://www.os2world.com/forum/index.php?topic=1433.0This poster indicates getting 2560x1440x32 to work . But it required setting up a new VM . Very weird.
I ran the following, and none of these resolutions are showing in my ArcaOS VM after reboot in the "Screen" dialog of Panorama. So, I don't think it's a 1600x1200 limitation blocking me. There is something else at play.
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global GUI/MaxGuestResolution any
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global "CustomVideoMode1" "1920x1080x32"
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global "CustomVideoMode2" "2560x1440x32"
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global "CustomVideoMode3" "2560x1600x32"
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global "CustomVideoMode4" "3840x2160x32"
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe setextradata global "CustomVideoMode5" "1366x768x32"