Getting skinnedmeshes screen rect cheaply

Sorry to link to another thread but it has diagrams
https://stackoverflow.com/questions...s-the-2d-box-immediately-from-the-3d-pipeline

Since this thread is a couple of years old, has this changed in the meantime?
Am I able to get this info from unity? As I assume it needs to know if an gameobjects skinned mesh can be seen by a camera, if not then unity doesn't spend time uipdating its meshes etc

At the moment I have to do a lot of calculations myself for a single skinned mesh to work out its bounding rectangle, and theres often lots of skinned meshes on screen, thus I'ld prefer not to spend the time unnecessarily

Cheers zed