My instructions do not say that, granted they are about 15 years old so maybe they were made better.
That's most certainly a possibility. I do recall a similiar warning on Accel super coils from back in the mid 80's.
As to the terminals if you are going to use the stock coil mount on a big or small block then the coil is in the horizontal position, you want to make sure the terminals are also horizontal, not one hood side and other intake side. just my two cents...