You can adjust the intensity and rate of the flash on the Hotshot, but unsure that it can be set to have a low power steady combined with higher power burst. There is a Cateye model that has two rows of emitters that can be programmed independently of each other- one row on steady and the other on any number of flash patterns.

Of course, any of the more powerful lights will give the impression of glowing after looking directly into it at full power...