Thank you @FaxLab3D and @sarahlenker for the responses; both lead me to the result I was looking for. I’m new to UE and always pleased at how easily things can be done, with the knowledge. For now, I’ll just go with what I’ve got, but I’ll make a note concerning resolutions and monitors for the future. My must needs backup is a widget with circles that scale from zero to some value to make them appear to come and go.
For anyone, who finds themselves here in the future:
I added a scene component to act as a permanent offset to the camera “lens” and used that location/rotation for the Niagara spawner. And, as mentioned, checked the Local Space option within the Niagara emitter.
Thanks again.