Edit: I’m glad so many of you have had no issues with multiple monitors. My set up is a little unusual (3rd display is an infrequently used large tv hooked through the receiver) and is definitely solveable but will take some effort (and honestly, I’d rather spend my spare time outside or with friends, so who knows when I’ll fix it.)
That’s a job for your bootloader
Well it’s not a problem in arm environments generally, just in x86 land, and the bootloaders don’t have a good shot of figuring it out on behalf of the kernel either… There is an ACPI table but no one cares about it in Linux land and is almost never used in Windows land (EMS does support it) and as a result most systems don’t bother doing it at all.