What do y'all use the LEDs for? Using them for layers (or other variants of "lock" keys) seems silly, since so long as you include a consistent "Clear Layer Stack" on each non-zero layer, it's faster to switch that way when you notice a typing mistake caused by being on the wrong layer.
Network activity?
WiFi strength?
Epilepsy test?
I thought some hardcore SC2 players could use it for APM thresholds, should there actually be an intersection in the Venn diagram of "ErgoDox users" and "SC2 Grandmaster players"