I just cant agree with that logic, unless both beams are crossing, in which case i still argue light management as they shouldnt be if you are maintaining proper buddy position and proximity. The cone of my light is at least 1.5ft past my head. Light doesnt go backwards unless reflected. Now I might agree, if the argument was my eyes adjust for the higher wattage beam, and a lower one may not register. That I could theoretically agree to. Or in the case where I'm lighting a specific area, in which case then the whole area is greatly illuminated (and probably reflected), perhaps more than a weak light attempting to signal can overcome.
a div team with weak lights, unless they maintain very religious buddy principles and proximity, is gonna be in the situation of not being able to signal each other.
I still believe that in our crappy vis toilet bowl of puget sound, a weak light is not only a poor investment, but a safety issue unless you maintain very strict buddy principles and proximity. A higher wattage light gives you a wider signaling distance margin if there is diver separation.
In addition, if you have aspirations to technical diving someday, a weak light is about useless, especially when you get into that Stygian darkness of Lake washington at several hundred feet.
So with all that said, a Dusty light is damned hard to beat. Its not a fish broiler, but is "useable" for tech diving. And because its not a fish broiler, its not bad for recreational users with perhaps less light management skills. I think its around 1500 lumens(but a larger spill), which while is greater than a DRIS 1k light, it'll give you hours of runtime, good signalling and light in more conditions.
So with that said, peace out, and we'll just have to agree to disagree