Understanding of SGIE

In the deepstream-test5 app configuration we can provide more than one sgie.

My doubt is
Q1: suppose i make all the sgie operate on the pgie output then does that mean sgies is running in parallel. If not then what is the flow?
Q2: Suppose 2 sigies are there, one is to detect pedestrian and one is to detect vehicle on the output of pgie, if i use a single egl sink with osd then can i see both the detection?
Q3: Can i make multiple pgies by modifying test5

Please provide complete information as applicable to your setup.

• Hardware Platform (Jetson / GPU)
• DeepStream Version
• JetPack Version (valid for Jetson only)
• TensorRT Version
• NVIDIA GPU Driver Version (valid for GPU only)
• Issue Type( questions, new requirements, bugs)
• How to reproduce the issue ? (This is for bugs. Including which sample app is using, the configuration files content, the command line used and other details for reproducing)
• Requirement details( This is for new requirement. Including the module name-for which plugin or for which sample application, the function description)