Scrog with 2 Screens

Will scrogging with 2 screens(one about 10cm above the top of the pot & another 30 cm above the top of the pot) affect my grow negatively?

What is the point of having the lower screen? It would have to have larger holes to accept the stems to go through. I guess I don't see the point since the idea of a SCROG is to build a green canopy to apply your light to, a lower screen would not be getting any lights...and 10cm is pretty low...