the LED will draw as much current as 3V3 standby will supply, unless you also have a current limiting resistor in place. likely much higher than 30mA. this will waste a small amount of power all the time and also decrease the life-expectancy of the LED. the 200 ohm resistor would waste less power (16mA / 54mW), but a larger resistor would probably work fine and waste even less. both of those options should work "fine," but i think they are worse than dropping in a smaller cap or doing redherring's standby voltage -> clock cap trick.