Various improvements, most notably the ability to control per-body whether contact recycling is allowed with "PhysicsBody.contactRecyclingAllowed" (defaults to true), the ability to specify initial PhysicsBody, PhysicsShape and contact capacities for any PhysicsWorld, various spatial-acceleration improvements and SIMD simulation performance optimizations. In best cases, nearly 50% performance improvements across multi-cores with high contact counts can be achieved for a simulation step.