I have compounded out 2-3 cars before and never ran into this issue, but I would not say that my prior experiences make me an expert. I have been given alot of advice that makes sense, and think I can get r done now.
In the past I have used wool pads to compound, however I let a friend convince me the foam pad was better, etc... and the foam pad vs. wool pad is the only difference in prior scenerios and this one.