I like to connect HDMI device to the Mavic. Is there any way to get the video feed as HDMI stream?
Is it possible to wirelessly connect a second iPhone to the Mavic, like the Goggles is connected?

to your first question: get yourself a device that can output HDMI, connect that to your remote and voila, HDMI output.
Second question: Yes, get yourself a second remote and connect your second iphone to that.

crystalsky

So you guys mean one can use the Mavic along with an atomos ? I own one and would LOVE to do that

I use chromecast streaming to my TV for liveview

Mavic supports dual remotes. You can connect a second mobile on the salve RC.