The answer for this question is there is no sufficient evidence to state that baby snakes are more dangerous.
Are baby snakes are more venomous because of concentrated venom in their sacs? No, There is no such things as baby snakes has dense venom in sacs. It is a myth many peoples do believes.
Another hot argument about snakes is that many reptile researchers and biologists claim baby snakes inject more venom in single bite because they have no control over their venom and matured ones only inject venom according to the size of prey and situation. The truth is adult snakes has more storage of venom in venom glands and are capable of injecting more than 10 times venom than baby snakes. So, even if adult snake injects controlled venom, it does not mean less in quantity. Comparing factors such as venom storage, a quantity of injection and biological behaviours conclude all venomous snakes are dangerous irrespective of maturity.
Fact: Only about 16% of snakes are dangerous to humans.