Effective way to update the display?

[nsmela]

We're looking to improve our 3D viewer's response and I had a few questions regarding it:

• pythonocc seems to use Erase to remove shapes from the display, but OpenCascade's documention shows that it only hides the shape, doesn't delete it. Wouldn't it be better to RemoveAll() instead?
• is there a demo on how to update an existing shape in the viewer?
• importing a small (2kB) mesh takes a very long time to add via display.DisplayShape(shape), is there a way to reduce the loading time? Like convert the mesh's shape into another object and then load it?