I have the exact setup that you have (Brigade & Shockwave).
I have the miniwave LED.
One thing that I've noticed is that you really can't let that
light dangle, at least not underwater.
The way it's weighted, it will hang with the light pointing up.
This weighting is great if you drop it. It will land with the light
pointing up so you can see it to go retrieve it; however,
its not good when actually diving. You need to hold it.
I clip it to my right shoulder D-ring while entering and exiting.
Once in the water and diving I release it and hold it in my
right hand.
I've tried and used a retractor, Carabiner, a fin strap,
coiled lanyard, and a quick release coil lanyard.
I prefer the fin strap or the quick release coil lanyard.
They seem easier & quicker to release or clip.
I don't like things bouncing around while walking or during
entry/exit.
The coiled lanyard was too "bouncy" for me and the light
would hang down by my knees when out of the water.
With a retractor, I'd recommend one with a stop/latch
I didn't care for the retractors the loose metal cable.
The Carabiner is cheap and works well but is more difficult to
clip/unclip, especially if you want to leave the Carabiner on your BC D-ring.
The quick release coil lanyard is by far the simplest and
easiest because you have a constant tether which can be
rigid or flexible/coiled
but never have the light attached to your wrist. It allows you
to have a free hand at anytime by simply letting go of the light.
Quick Release Coil Lanyard
I like the fin strap because its dual function. It does require
attaching/removing the lanyard to your wrist if you want a tether
on your light.
Alot of it comes down to personal preference.
--- bill