Re: Flash Matrix...
Yes, and of course you rename the files properly.
Re: Switch.
With some LPC mods like the Matrix, you can choose which bios your system boots with (dependant upon the dip switch settings!) by how you turn it on.
Pressing the power button gives you the LPC bios, pressing the Eject gives you the original BIOS.
With other MODs you'll need to install a hardware switch.