Thanks. So, basically, unless you loc-tite the BR nut to the QR clamp, you still run a risk of it unscrewing?
Not sure - if you slightly moisten the rubber compression washer and screw the lug in tight (with the solid aluminum, no risk of overtightening), probably not. But I see no reason to remove it routinely, so why not use Loctite? The Blue 242 type is semi-permanent - it's not going to come loose with normal use, but with a vice and a pair of pliers you can unscrew the lug.
Adding the Kirk1 clamp seems like a reasonable idea, but it just seems to be adding another point of possible failure. I would think the BR screw in post with the rubber ring would stay tighter than a clamp. Has no one ever had the clamp work its way loose?
I disagree. With the Loctite, I wouldn't classify the lug-clamp connection as a failure point, so you're certainly not adding one. Moreover, if you frequently unscrew and reconnect the lug (which you'd do to attach to a tripod, for example), that makes the lug connection a much more likely failure point. There's no rotational stress on the clamp screw, so it won't come unscrewed unless you turn it. Orientation prevents unintentional turning - on a body plate, attach the clamp so the knob is under the lens, on a lens plate, attach it so the knob is away from your body. I've never had the clamps loosen even a smidgen. So, overall, I'd say the BR lug attached to an AS-type clamp (the Kirk or RRS' new flat-bottom clamp) with Loctite, connected to AS-type body/lens plates, is both more convenient and more secure than directly attaching the lug to a tripod socket.