LED_INTENSITY - controlling a led by a RF transmitter
LED brightness is controlled by current, not voltage. In a LED-resistor combo, the voltage (minus the LED forward drop) actually controls the current flow. This device provides a current-controlled output so no resistor is required.

As for the low available current on that pin, many small SMD indicator LEDs will provide sufficient light output at 1ma, Such as this, which I found with a very quick Digikey search.