I'm sure there was something that contributed to it. I've known alot of people with 6boost manifolds and don't recall any issues. Mine has been faultless
Frankly, I think its a bit crazy to blame 6boost for being shit when he bought a car with it already fitted but 'never used'
Who knows what the previous owner had done. Also I was told not to use heat wrap etc on mine, Perhaps it had heat wrap on it and cracked for that reason?
I've had mine on the car for 2 years, zero issues. It looks pretty much the same today as the day I got it, no signs of heat stress etc
I'm not trying to say they are the best manifolds in the world and nothing else compares...... But they are a very good product