Ah an another suggestion. compound collisions are very efficient, but that does not mean they are the solution to everything.
For example if you have a shape that only have one convex hull, if you make it a compound of only one shape, that will be efficient as compound goes, but will never be faster than a convex hull shape.
That's a cathegory mistake people do, they tend to compare one class of objects with a different class of objects because one can do the job of the other.
similarly, of you have a Box shape that could be represented by a convex Hull, but the Box because of its nature always do the job much faster.
same goes for things like cylinders, you could do it with a high definition convex hull, but it will never be as smooth or as fast as the primitive.
this is one for the reasons why there are some many specialized shape in the engine, is the job of the end application to select the correct tool for the correct cases.
I say this because It seems you are using compounds as the generic collision shape.
or maybe I am wrong in which case ignore this..