Multiple user generated btManifoldPoints at the same place

[frca]

Hello,
I am implementing my own collision detection between static world and moving body (collisions between two moving bodies are handled by Bullet entirely). The generated manifold points have m_lifeTime = 1. I never call btPersistentManifold::clearManifold, just refreshContactPoints. Quite often happens that there are multiple contact points at the same place on the moving rigid body. Is it ok or should these multiple contact points with the equal moving body's local coords be avoided?
It works quite nicely, but I have no idea if it affects simulation accuracy or not.
Thanks