Cinemachine not affect Main Camera?

I have a VR project and I'm trying to achieve the player being able to watch footage on a TV screen in the room. The TV screen is a render texture. So two camera's in total - the player camera, part of the XR Rig, and the "TV Camera" which has the cinemachine brain and outputs to a render texture.

The virtual cameras pan around the room and should output to my render texture. This should not affect my VR rig's camera, ideally.

However, as soon as I take the camera (not associated with my XR rig) and output to a render texture, the cinemachine brain wants to use my players XR main camera.

Is there a way to force the cinemachine brain to use a separate camera so I can achieve what I need to achieve?

 

Perhaps poor wording on my part. The Cinemachine brain affects the camera tagged MainCamera, which belongs to my XR rig. I created a separate camera (untagged) for the Cinemachine brain/sequence. However, at runtime, the sequence uses the XR main camera. I'm guessing it's impossible right now based on what you said though.

I'm basically trying to create "spectate" cutscenes, similar to RE4 VR, in which the player watches the cutscenes on a camera render texture plane, if that makes sense. I'll keep an eye out for a Cinemachine update in the future, I suppose, or cut the functionality for this project.

 

Thanks, apparently that was the problem. I appreciate the help.
One last question! I'm using the Storyboard extension to do a camera fade. However, this fade effect doesn't seem to work when outputting to a render texture (everything works okay on the output texture, except for the storyboard). Is there any work around for that/suggestions? I guess with this particular setup, I could place a canvas over my render texture and trigger the fade-to-black that way, but I wasn't sure if there was something I was missing or if it's just an incompatibility.

Thanks again!