The preview image Fov on the phone is less than 50% vs. the final image, this can be changed? I can not believe, compose a photo in these circumstances is not very good Image atached.
It looks like you have your video FOV set to narrow (90°). I noticed previously that this affects the iPhone preview FOV, even though you are taking stills at full 140°. Try setting for 140. See Video Resolution in the manual for instructions (page 41 of manual v1.10.)