How can I make FastLED set every 2 LEDs to the same color? I'm controlling an WS2812 LED strip in which every 2 leds is controlled together - they are setup as "eyes" in a prop.  I'm looking to control hundreds of these, so in an effort to save RAM I'd like to have each byte in the LED color array represent 2 LEDs.  That is to say that when the FastLED library writes to the data lin I want it to duplicate every byte going out.

I've dug into FastLED code but get lost around the timings deep down in the code.

Any ideas?
The FastLED community appears to live at this reddit.com site. Consider asking your question there.
It is unknown if the following will exceed the current limitations of the Arduino platform you are using.  But, consider sending the same data to two different strings of LEDs simultaneously.  Briefly, each LED strips off the 1st packet of data and sends the balance of data through to the next LED.  Two different strips should behave the same if given the same data.  Thereby creating the effect you described (pairs of LEDs behaving the same).