The first rule of "The Launch Pad" kits is to discard the instructions. As per the instructions included, the typical margin for error is great, and the product is intended for builders that can negate the narrow stability margins inherent with most of the scale or semi-scale representations of the missiles depicted.
I personally use a patch of Nomex in my rockets, and that is what I do with my Launch Pad Kits. I tend to build a heavier rocket, but I make sure the weight is mostly toward the nose, so my stability is at the peak of what it can be. The proof of my techniques are represented in the actual flight characteristics:
[video=youtube;n_4PixwVYug]https://www.youtube.com/watch?v=n_4PixwVYug[/video]
[video=youtube;FHFeGZLoORE]https://www.youtube.com/watch?v=FHFeGZLoORE[/video]