In this situation, the light will be left on for probably 3.5 hours during a rave. It typically starts at 10:30PM and goes until 2AM. So, turning it on and off rapidly won't be an issue.
A 30 minute warm-up time? Wow, that's a tough one, but I don't think this scenario would have it take that long to warm up since the light will have been in the room a good long time and will be at room temperature. I suppose as soon as the band is done, I could fire them up. But 400-watts per fixtue is a bit much draw, considering this venue has crappy power access. I also have to run LED lights off this circuit, as well as the DJ gear and monitors. I might see about trying to get the hotel to run a power distro with plenty of juice on tap next time.
In the Repo! show I work on, I should post what that scene does. I go from a wash to blackout to the 64 LED UV. Then short blackout, back to wash for a bit, then blackout and to UV again. Repeat one last time. The times are different each of the times. I got about 1.5 seconds of blackout to get the UV fixture on. I sent Jingles a picture of the UV ligting up the girl.
I think I might go with the UV Washes mainly for the money side of things. I think the UV cannon would be the better solution but I don't want to spend the extra money right now.