@dusxI I have actually done just that now. I did test sending directly from my system over a hardline into a capture card for the streaming server. I then tested setting my stage output to spout and using Spout to NDI to send the feed via network to the same streaming server. The Spout to NDI handled things the best just slightly. Which I found surprising.
My guess is that the layers don't read across scenes?
The default layering mode does not read across scenes, rather it 'flattens' each scene to provide the cleanest possible scene transition.
There is another layering mode available, that does not flatten scenes, and provides the cross scene layering you were looking for. Note: You can change the layering mode for the entire project only. The setting is available Under File/Layering