To stop the text jittering you would need a fix-width font. Like a mono style font. I don't notice the jitter as I used the user space font mod to change my dash font so I don't see it. Hopefully the new settings system will have custom font options also?
Been struggling with this myself! Apparently it only works in VR mode. In Resonite in the Camera Control Window, click on Mirror to Display. The camera view will now show fullscreen on your Display. In OBS use the game capture source and grab the Resonite.exe window.