How do I edit and export with 360° (VR) metadata

While LumaFusion doesn't currently have a full VR workflow (with VR viewers), it will allow you to edit a VR timeline and export with the proper metadata so that the VR footage appears correctly in Youtube or facebook.

You will normally create a project with a 2:1 aspect ratio (which fits the stretched surround footage).  You can then import VR video and photos and add to the timeline.  You can trim and cut as usual, add effects and transitions.  Note however that some effects that move pixels (like Kaleidescope/etc) may ruin the 3D effect.

You can of course also add and edit audio as needed.

When you export your movie, simply change the 360° VR Setting to 360° mono (this is the most common form for VR footage.  Some cameras have stereo cameras and produce either top-bottom stereo footage or left-right stereo footage).