I have been playing with fin styles for my big crayon. From a typical 4 fin arrangement to 3/4 fins with winglets like the Jayhawk to a near minimum diameter ring fin like some people use on water rockets. I had wanted to keep it very light, but it needs big fins, nose weight, or both. When it gets heavier, the pink foam parts seem less ideal. I'm now thinking about cutting some ply rings to support bigger fins and then just stuff in whatever weight is needed. But then I might want to move up to a 38mm mount. Sigh.
So, the only real progress has been to cut up a PVC fitting to make an el cheapo motor retainer. If not used on this rocket, it will eventually find a good home.