Let's say you tell someone to do something, and they say "ok". But when you ask them later whether they did, they say "oh no, I just said ok to indicate that I heard you, not that I was going to do something about it." That doesn't make any sense. The indicator light has the same function. Going on and then off again is a violation of basic communication protocol.
The more complex the intersection, the more controls I can watch, to get a feel for the rhythm, patterns, and triggers that influence the cue to activate my “WALK” signal.
I’m also watching the cars to see when the flows slow down or stop. I should perhaps pay more attention to the signal that pertains to me as a pedestrian or motorist...
I guess you might want to fade it from red to green (red being "this works" and green being "it'll do what I want"), but I don't mind the holding-down behaviour. The only problem is that you can never know how long you need to hold it down for unless you stop holding it.