Speeding up CPS3 rewrite process

I was checking with MAME experts about how to speed up the process of rewritting a game in CPS3 and I couldn't find any part of the code where this happened, so they told me that the problem is that the WD33c93 is a programmable SCSI controller and the code to read the CD is being transfered from BIOS to this SCSI controller.

The code is so shit that that's the reason why it takes ages....I'm quoting:

"On the real board it takes just as long and [...] it isn't caused by the FLASH being slow, it's caused by the CPS-3 BIOS code reading the CD very slowly. It isn't MAME's code you'd have to hack - it's the CPS-3 BIOS code itself that causes the slowness."

That means room for improveness of the rewrite process with a new BIOS. Anyone wants to try ;)