Funny you mention using the RGB for video. A little while back I was thinking about that light for the same purpose. I did some half-hearted Google searching but not much since I figured they were probably long gone by now.
Unless you maybe give Chauncey a few gold bars, and possibly a few spare body parts, to convince him to part with one of his!!
Anyway, back to video, I tried a lot of my lights to try to find what was best, including some make-shift diffusers like white plastic grocery bags. Turned out that the best was the little AAA Lumintop EDC01 (has the pebbled/honeycomb TIR optic). That puts out a very smooth beam that doesn't show a blown-out hotspot in photos and video.
Might not be enough lumens and/or runtime for your application though. But I did just discover there is a AA version of the same light (EDC15). I was making a small purchase on Amazon anyway, and it was only like $17 so I threw it in the cart too. I don't trust any lumen specs anymore so I'm just waiting till I get it to see what it'll actually do.
Not that I'm trying to talk you out of the D4K though!!