It's really just the VR visor that needs docked performance and the tablet slides into that so the same docked recognition could operate in that anyway so effectively VR and docked is full performance and portable is always 150 gflops even with an external usb power connection.
You could render at 1080p internally and downscale to the 720p screen to give a marginal image improvement but its not going to be a huge difference in quality on such a small screen so probably not worth doing. However there are other options like wireless display where you could take you Switch with you and without a dock send a 1080p image to a tv but from my experience this is very laggy and not good enough for games. However it worked on wii u and later versions improve on this. I've only tried it from android tablet to tv but it wasn't great. Fine for movies and non-interactive stuff though.
