If the BIO BBs carry enough energy to break on impact, enough energy has been imparted at the tank to break the BB. Conservation of energy.

A misfeed, out of spec BB, etc is all that is needed to cause a problem. Suite yourself, have fun, but don't say a such a thing won't happen...it will, to someone. Just because it hasn't happened to you doesn't mean it won't. I personally choose not to use that kind of ammo in my tanks...I stick to AE .25s, the same ammo I shoot out of all my airsoft guns.

Also, keep in mind that VsTank, ToyEast, Tower Hobbies, whoever you got your tank from, they likely won't have much sympathy for paintball users. Have fun, but use at your own risk.