I know Mavic and the Goggles are connected wirelessly. However, I heard the Goggles can be connected to Spark remote controller with USB OTG. I wonder if I can use cable to connect the Goggles with Mavic remote controller, and whether the physicial connection can result in better video.
The controller has a USB port in the middle. If I connect it to the Goggles, what would happen? I hope it works the same way but with better video transmission. (I don't have a USB OTG cable yet. I want to ask before buying one.)
The controller also has a port on the left, which is used for charging and for connecting to the cell phone. It doesn't look like a USB port. What is the port? Can it be connected to the Goggles? I wish I can fly the drone with the controller and Goggles, but without a cell phone. The cell phone seems no longer needed, yes it has more features, but not it becomes cumbersome with so many different devices.

Sorry if I sound clueless. I don't know how these things are working together: drone, controller, cell phone, and now goggles. Do the Goggles and the controller receive video from the drone separately, or the Goggles get video from the controller? Why would I want a SD card on the Goggles? Videos and photos are stored on the drone, not the Goggles.

To illustrate my question, I draw a picture. Dotted lines are wireless and solid lines are wired connections.

I know for sure connection A and B exist.
I don't know how the goggles is connected. Is it via C to the drone, or D to the controller?
If there is no C but there is a D, can I replace D with a wired connection E?

If E exists, I'd rather remove B and the phone from the picture. The phone becomes so less important.

C is Ok.
D and E are not possible.

Mavic and Goggles are both using OcuSync so you do not have to connect the Goggles to the remote controller. However, Spark do not use OcuSync so the only way to connect is using the remote controller USB port. I don’t think wired connection improved the video quality since Goggles connected wirelessly to the Mavic so the video quality will still be the same like what the remote controller shows.

Is it possible to connect a lightning-to-HDMI adapator to the lightning port on the Mavic so that I can plug the HDMI end into my HeadPlay goggles?.
First question - will it fry anything! I jusr bought the Mavic yesterday!

Hello, the answer is NO !