I haven't heard anything about them but I have a couple of opinions.
Using two 18650s at 200 watts will draw 37 amps from each when they are close to drained. There are no 40 amp 18650s on the market, most are only 20 amps. They claim it uses a prorietary chip. Considering what they consider safe battery wise, I would worry about what safety features they have on the chip and how good the chip is overall.
Agree. I don't see anything about short protection, heat protection, low battery protection, etc.