Given that the decent blinking rear lights will get noticed from vast distances even in daylight, I find the hypothetical depth-perception benefit (if it really existed) is a moot point. Getting on the radar early, before they resume looking down at the text message they're composing on their cell phone, is the main concern, and that's best done with blinking mode
Seriously, I have no problem assessing the range of a taillight like a SuperFlash at distances approaching 1/2 mile. I can't see through anyone else's eyes, but is it really a problem for any of you? By the time I'm anywhere close, I've already been watching them for quite a while, it's not like WHOA, ALL OF A SUDDEN HE IS ONLY 100 FEET AWAY, HOW ON EARTH DID HE GET THERE?!?!1
Guess I should add that in my firsthand experience riding divided 4-lane highways, people see my all-blinking bike and change to the left lane at long range, like >1/4 mile. I even have some video footage demonstrating that. Getting noticed trumps everything else, IMO:
At about 1/2 mile out (about halfway through the video), if my lights weren't flashing, I think many overtaking motorists would not conciously take note of them. And that's the range where a semi driver would probably start assessing his zones to make a lane change and stay away from me.