I understand you’re talking about Unity- Yes. it’s a bit more difficult, but basically, you render a second camera to a renderTexture and do something like camera.targetTexture = myRT, and then pass that rendertexture’s nativetextureid to the plugin.
I am having the same question: How can I send two or more camera outputs from Unity to Syphon?
Unfortunately I can’t figure out how to realize the solution in your description. Could you (or someone else) maybe give some more details of how to set this up?