I appreciate the insight, and I have heard about how helpful the use of material instances can be. However, answers like yours are part of the reason why I’m concerned about Epic’s lack of transparency 
I’m a long ways off from making anything complex enough for shader complication stutter to be an issue, but with the subject coming up more and more I’d like to learn how I can mitigate or avoid it when the time comes. Epic simply saying “we’re doing automated PSO caching” and then walking out the door just isn’t enough for me.