VideoTexture with viewports

Hello, I’m trying to render the contents of one camera onto a texture on an object, but I can only get it to display the active screen. I try passing ImageViewport ‘OBCamera2’, and while it doesn’t throw an error, it also seems to just ignore it.

Is this functionality just not implemented yet?

edit: this is with revision 17496 on ubuntu

its still not implemented, but will shortly