This is done by xbtool when you apply any patch, the dash loading function is replaced. The only way which you could change this third, 'unconfigurable' .xbe is to unpack the bios and hex edit the kernel .img.
If you're concerned about going on to Live with your modchip enabled, just use the X2 4981/4983 BIOS; you cannot connect to Live with your chip enabled with these kernels.

Now the bios has no idea what xboxdash.xbe is and will never look or find it.