After 5 months of building my bike from ground up I had the chain fly off today. Messed the plastics and frame up pretty good but thankfully no hole in the block, just broke the sprocket guard. Bike is stretched but nothing too crazy and it also has -1 + 2 combo on it with a .530 rk riveted chain. My question is what are some things I could do to insure that if the chain comes flying off again I can add a little protection so I won’t have to worry as much about putting a hole in the block along with slimming down the chances of the chain even coming off again. I was told to run the chain tighter but some people say looser with it stretched. I just know I do not want to put another hole in the block so any recommendations would be appreciated! Thank you!