I have raised all my kids on replacer, none have died. It's as simple as following directions and being smart enough to know how to do so. If you don't follow the directions, don't measure stuff out, don't use the correct temperature of water, don't mix it well enough, you might have troubles. If you can read and measure you can feed milk replacer without any troubles. It also pays to buy a good quality one made for goats as they are basically powdered goats milk.Are there any numbers of guesstimations on let's say out of 100 replacer fed goats what % would die? Is it closer to 1:5 or 1:10000?
Just because someone claims to have done everything and knows everybody doesn't mean they know what they are talking about. Why would they make a product that kills, there's no profit in it. Follow directions, it's as simple as that.