I don't know if changing firmware to default to max speed is a good idea with SCSI. It might make the controller incompatible with lower spec devices.
A better method would be to work out the sequence of commands sent to the controller to turn it to the higher speed mode, and stick such a command in your startup-sequence. How this could be done is beyond my knowledge, I must admit. I haven't booted a SCSI device for some time now.
But it saves the risk of messing up the firmware, or maybe making it incompatible in other ways. If it ain't broke, don't "fix" it.
Others may disagree of course.
