With NghtShd making threats of not updating XBtool, I took it upon myself to make a simple Windows utility to customize the latest Xecuter2 bios. It's based on the work of skorchir and 82ross, found here: http://forums.xbox-scene.com/index.php?act=ST&f=38&t=153934

This will allow you to do the following:

The 4981 fix, msxboxdash.xbe->xboxdash.xbe.
Change boot partition between C/E/F/G.
Disable the trademark, splash, and animation.
Customize the boot colors to your liking.

I've tested this extensively, and it's as reliable as the hacks are. Anyone who knows me from the Dreamcast scene can speak on my behalf.