The problem (booting from CDROM) is that the floppy bootloader has to leave a TSR(1) (a BIOS driver to simulate an El-Torito(2) disk) in memory after it has transfered the control to the CDROM bootloader.
That ATAPI driver cannot be written in protected mode, like the GRUB2 driver is.
IMO only one bootloader can do what is needed.
(1) Terminate and Stay Resident, i.e. an interrupt handler in real mode with its code below the 1 Mbyte barrier.
(2) The way to boot a CDROM is to simulate a BIOS "El-Torito" disk