it will work just like it did before.
the only thing i'd think about is this (and i dont know since i dont have one)
does the executer 2.6ce modchip allow you to boot from different bioses. By this i mean, can you put 2 bioses (the one you have now and the ind-vga bios) and pick which one boots.
You wont want to have the ind-bios running all the time, only when its hooked up to the monitor.
since you have a flat panel monitor, the x2vga will be more compatible (i think, but it has problems too).
I think your best bet would be to try and make a homemade cable (very cheap), and if that doesn't work go and buy the x2vga.
The only downside to the homemade cable is that a few games dont work (KOTOR, Jade Empire, etc) and that it needs a moded xbox.
But, i'd rather make a cable for $20 then spend another $60 to buy one.