I've actually started riding with two lights. One light flashes bright and the other is on steady. This is basically what my Dinotte 300R rear light does (stays illuminated at all times and also flashes). What I've noticed is that a flashing front light alone is hard for drivers to track. A steady light alone is not bright enough for drivers to notice in direct sunlight. The combination of both works best IMO as the driver is drawn to the flashing light and they can easily track your movement with the steady light. I do wish light manufacturers would make a front light that does both and is bright enough to be noticed in direct sunlight.

Let's face it, most "cyclists" have woefully inadequate lighting (if any at all) so any research on daytime lighting is going to be pretty much useless.