Should be pretty safe - maximum current should be limited to about 6A to stay within reasonable limits, so I would stay over 0.6 ohm if I were you.
4.2V at 0.6 Ohm = 7A
3.7V at 0.6 Ohm = 6.2A
Manufacturer data here:
Never underestimate the power of human stupidity.
All opinions expressed are my own.