Reading vertex position for physic simulation

Hey there, I want to implement a position based dynamic for custom cloth simulations, problem is that I can read easily the vertex position from the base mesh, but, for what I want to do, I have to read the vertex position IN OUTPUT from the modifier stack and then modify them before they go in the next level of the stack, otherwise I cannot use the rig animations and particle systems/subsurface/smooth for more complex effects.

Is there any way to read and write the vertices in some inter stage of the modifier stack? Or any other trick that could me allow to do so, avoiding to bake the whole animation as blendshapes sequence possibly?