How to efficiently trigger QC and convert it to constant 5V and a peak of 5A?
The way I solved this in the original macetech RGB Shades:

Full power is too much, cap it in software

It turns out that running 12-15 watts of LEDs on your face is too much. I have customers asking me frequently for reduced brightness levels, even though the stock RGB Shades firmware ships with brightness capped to 1/3rd of the maximum brightness (with 5 adjustable levels reducing the cap to less than 1/10th the possible brightness).

If you're in a darkened room, even 1/10th brightness over 68x3 = 204 LEDs can be quite blinding. Running them at maximum brightness also can cause the panel to get hot to the touch and physically uncomfortable.

By shipping the shades with brightness capped in software, they run fine from a normal pocket-sized USB power bank. Customers still want it dimmer, so there is no need for a high-current supply. Designing for maximum LED output is a distraction in this application, you will find yourself looking for ways to reduce the current, not increase it.

Filter analog supplies to reduce power rail interference

With normal USB cables, we saw pretty significant power rail bounce depending on the LED pattern. This interfered with a later MSGEQ7-based microphone audio sensor. The solution was to use a small inductor and resistor to filter the power rail, and to have custom power-only USB cables made that both had thicker power conductors than normal USB cables, and were thinner and more flexible than normal USB cables since they only had two conductors.

Much of the audio-specific design process is captured here, if you need additional information (and OSHW design files): http://www.macetech.com/blog/node/144