I have done the same...the MSD Grid I use is infinitely adjustable. When I add the nitrous to this engine it will automatically pull the timing I type into it as soon as the nitrous solenoid activates Is one thing but there are so many other things it can do. You can put a fiber optic on #1 plug wire and you can actually change the timing per hole...Fun day at the dyno! Can't belive ya hit 924 at such a low rpm. Amazing!
A trick I used to do to do with timing at startup was to turn the ignition power off, but keep power to the starter. Get the engine spinning first then turn power on to the ignition. That way the starter motor isn't fighting the advance in the timing when first cranking. Pretty low tech compared to what you're doing.