Spent some time really laying things out in Fritzing. Here's the diagram:
I didn't label the tac switches on the LED rows, but they are for row select. The Big cap in the middle next to the Trinket Pro is a 1000uF, 35v cap. The docs on the NeoPixels recommend a "large" capacitor across the power lines before the first NeoPixel, to protect the NeoPixels against inrush current when the circuit powers up. The docs recommend 1000uF, 6.3V or bigger, and I had the 35v laying around. Massive overkill, I know.
The switch on the far right drops the ENable line on the booster/charger to GND, cutting it off.
You'll note there is only one data line going into the LED array. I'm debating whether or not to leave it like that, or split each row of LEDs into a separate control line. I don't really *need* to split it out, but it might make my software design easier. Or harder. I
ll have to play with it.