Hey there !
glad to see that this MOSFET option was in the mind of someone else. I talked about this option in madcow thread about relay problem with a MR board.
MOSFET mod is a great idea, much better than using a bipolar transitor.
My initial idea was to use the 6 output of the MR to control a ramp to the mos fet to get a ramp up/down effect for the luxeon.
Minimum effort, max performance
but I haven't got the time to test that...
I'll be pleased to help in this field and comment / improve / exchange on a schematic from neophyl !!!!