That is stupid. Sorry but that is a dumb product. Most people want narrow Q-factor and if you have knee pain, toe-in usually cures that by taking stress off the knee.

You can toe out but the amount they are advocating is ridiculous and will probably cause injury.

If you still want to blow $50, it's just a simple extender so it shouldn't break. It will increase the leverage on the crankarms so you might get more flex or stress on the bottom bracket and arms but I don't see any problems.