Nope

echo 1 > /sys/class/leds/gl-mt300n:wlan/brightness
-ash: can’t create /sys/class/leds/gl-mt300n:wlan/brightness: nonexistent directory

I’ve even tried

echo 0 >/sys/class/leds/rt2800soc-phy0::assoc/subsystem/rt2800soc-phy0::assoc/brightness

/etc/init.d/led restart

echo 1 >/sys/class/leds/rt2800soc-phy0::assoc/subsystem/rt2800soc-phy0::assoc/brightness

/etc/init.d/led restart