Sorry, I misunderstood you.
I'm surprised you'd find a side mounted light inferior to a center mounted light. I find when I use one of my flashlights on the side of my bike helmet while cycling, the slight offset to the side actually aids my depth perception rather than hindering it. Indeed, I find I get more tunnel vision, not less, when center mounting a helmet light.
With night rollerblading into driveways and porches it's different.
You want to be able to see anything and everything that is directly ahead of either you or your possible new path.
Having a light on the side of your head both:
1. Cuts the output down because it's lighting up a portion of your head
2. Makes you have to compensate your aim for left and right - which under most circumstances wouldn't be too big of a deal, but when night skating the last thing you need your brain saddled with is having to make compensations.
You want to be able to look, and see, instantly.
Furthermore, we've discovered that a light mounted to a hat bill is much better for scanning possible paths. The Zebralights could be mounted this way.
With any form of head mount (we've now tested this with some cheapo dedicated headlamps too) you have to twist your head more to see.
Depth perception isn't a concern - there was some talk about shadowing (or rather lack of) via head mount in another thread I posted.
It turned out this was completely irrelevant for this application. At least for us anyway - we all have decades of skating experience, so we apparently know how to identify hazards via center mount head lighting and shadowing isn't necessary...
It's far more important for us to have a beam centered exactly where we look...
We actually NEED "tunnel vision" - but with the ability to sweep it around as needed...