Looks very unstable, but guy is probalby minning some ubercrapcoin. Eitherway L3 looks nice but given S9 issues and first scrypt miner from Bitmain, i wouldn't trust it. One breakdown a year and you will lose all you gained from electricity.
If it is really L3, I'm impressed. Now probably after overclocking it hashing at 300Mh/s average or it's scam.
Not a scam just minning some crapcoin with probably low diff. I can also get almost 400Mhas on some peaks on A4.