Just to let you know, I had some problems with getting the important item Unbreakable Sword dropped by the Brute Millepod with the Custom Materials Drop Ratio code configured with 100 %.
It is an important item that normally is always dropped at the time of the mission but which never does with the code active.

I had a similar problem during the Lakeside Getaway mission. When you defeat Raging Cantor at the Primordia's Biahno Water-Purification Plant, you normally get Ian’s ID Card important item. But with the Drop Ratio code active I never got this item and I was stuck with a dummy mission I could’nt finish until I fiddled with cheat engine to forcibly place Ian’s ID Card in my important item list.