Can not mount off the Large disk

This might be resolved by disabling the udma.
if you say that BIOSes provide switching between PIO0 to PIO4.
but there is no way to control UDMA in a BIOS.
Because every Operating System (without DOS) is taking control after the bootstrap over the hardware and even FreeBSD.
If the kernel is taking control. Use switches at the loader prompt:

set hw.ata.ata_dma="0"

This will load the drive without issue.