As an introduction I would like to share my setup as used for an online TV Talkshow
This is the schematic view
The AMP will do the video-switching and streaming to local or external servers.
The streamdeck is the input to the companion SW.
The companion SW is able to send instructions to the AMP ( switching video source directly )
The Caspar-CG server can also receive instructions from Companion ( f.i. Starting playout and animated Lower thirds )
On the Caspar-CG server commands can be placed in a group and executed as a row of instructions to the AMP ( selecting Keyer state, selecting output, Start macro, start playout )
In this way complex switch situations can be performed.
This setup is used to stream an entire talkshow with prerecorded clips and slideshows between the interviews and Lowerthirds for the persons talking.
By using a software based ( freeware ) playout the budget is kept low without concessions in reliability of switching and streaming with nearly the same capabilities of OBS.
The raspberry pi is able to receive the program stream from the AMP and in this way ( when not streaming to the internet ) the Pi creates a program-out view on the connected display.
This is useful for program view in a nearby room or even recording the program out while using the USB as a webcam output.
( Keep in mind there is a delay between the stage-performance and viewing the program-out )