Don't use super bright lights on your helmet on urban roads because it will definitely blind oncoming traffic. Using a light with a cutoff beam like stvzo may be better but mounting it so far up will make the beam shine into people's eyes, and these lights are meant to light up the road instead of just to be seen. If you want to see how it's like to be blinded, place the activated light on a window sill or table at eye level and stand maybe 10 to 20 meters away and look directly at the light while in the dark.

I made my own helmet light magnetic mounts.
Helmet breakaway lights DIY with magnets
I used $5 lithium polymer lights that are meant to be seen that have an extremely wide beam so you can see it up to 120 degrees. There was some glare when looking at it directly so I added a translucent PVC privacy film to diffuse the light so it's not uncomfortable to look at in the night. The battery lasts around 3 to 4 hours on low output mode. I wouldn't use flashing mode because it's very distracting and also illegal where I ride.

I originally used topeak headlux lights but the button battery dies in cold weather in under 5 minutes. In warm weather it last a few hours.
Helmet breakaway lights DIY with magnets

Also fixed attachments on helmets have a risk of causing injury in a crash, which was why I made my lights attach magnetically. They will slide off with around 300g pressed against them.