Just another question. Maybe someone find it useful too.

Which boot protocol is it wise to use for an amateur operating system kernel in modern times?

Multiboot 2, UEFI, Limine boot protocol or some other?

Is it possible to support multiple boot protocols in the kernel at the same time?

As far as I understand how this can be implemented, you need to specify at compile time which protocol to build the kernel with and, depending on this, build the kernel differently for each protocol. Am I right?