Well, regardless of if my LED's will work-- your stuff with the spark gap is STUNNING. I read the original writeup when he first did it.. still one of the best Mad Scientist projects I've had the pleasure of seeing written up. I've been tempted to make one, as you did. I must admit those kind of voltages give me the heebie jeebies- I once got a taste (via a slip while trying to adjust it) of a flyback transformer in a monitor, and there's a good reason why it's called a flyback- it's pretty much what happens. Hand was numb to the elbow for days..and I was lucky that's all.
I've always considered whether a mechanical (!) shutter (like a rotating slot in a disc) could further shorten strobe length, in that you could sync the strobe ignition and the passing of the "slot" shutter so that the strobe duration was limited by the physical barrier of the disc. Never done the math on it, I suppose the factors in play are the size of the slot/window in the disc and how fast it's being spun. I would think that using a photodiode (infrared!) and LED, you could sense the slot as it passes, and therefore be very accurate in terms of timing, and the idea would be to trigger so the flash begins during the passing of the window. The light is "interrupted" (in terms of what comes out) by the disc then blocking it. It's a project I want to try, and it wouldn't be very difficult to at least do a proof of concept. I guess I'll have to sit down and actually do the paper design and see what the issues would be...one that I have considered is that the rotation speed/effective size of the window could be drastically reduced by secondary (or even more) disc/windows being rotated in the OPPOSING direction, by varying the speed of rotation, the windows would only align for VERY short time periods even at reasonable rotation speeds.. mechanical stroboscopes are far from new, but combining them with other technology might just work.. hehe as I sit here and think about it, I'm envisioning a stack of counter-rotating discs.. and then instead of a triggered strobe, just good old Thermonuclear Fusion.. mount the thing in a window or skylight, use a few mirrors....