I get only 720p on the Go app with my OnePlus 6 and Osmo Mobile 2. Sold my OnePlus 5 and there I got 4K with example HyperLaps. Any support for at least 1080p with OnePlus 6 in the future?
My info from a clip with OnePlus 6:
firmware version 2.2.0.30
#Thu Aug 02 11:32:07 GMT+02:00 2018
Sync_Drone_Time=
PixelYDimension_Local=720
PositionGPSAlt=-100.0
PositionGPSLng=-100.0
ProductType=45
PixelXDimension_Local=1280
LocalFileName=/storage/emulated/0/DJI/Camera/DJI_20180802_113155.mp4
CameraType=
Video_Resolution_Enum_Drone=-100
WhiteBalance=-100
FrameJumpped=0
Version=1.0
PositionGPSLat=-100.0
EndTimeMsec=-100997534
FPS_Drone=-100
FPS_local=30
PositionRelativeAlt=-100.0
Sync_Local_Time=
FolderID_Drone=-100
ExposureMode=
CaptureDate=2018/08/02 11\:32\:07
File_Source_Type=1
PixelYDimension_Drone=-100
ImageDescription=
Is_HD=false
LocationString=
PixelXDimension_Drone=-100
FileID_Drone=-100
UUID_Drone=-100
ShutterSpeed=__UNDEFINED__
ISO=-100
DeviceMaker=DJI
ApertureSize=-100
StartTimeMsec=0
Source_File_Path=/storage/emulated/0/DJI/Camera/DJI_20180802_113155.mp4

Hello there. I appreciate your time bringing this query to us. In regards to the resolution, that will really depend on the capability of your mobile device to do so since the Osmo Mobile 2 will only work as your gimbal. Upon checking on the website, Oneplus 6 is not compatible with Osmo mobile 2 so we highly suggest to use a mobile device that's compatible with Osmo Mobile 2. You may double check it here: https://www.dji.com/osmo-mobile-2/info#downloads

It say; When recording video, video resolution is set at 720p in DJI GO by default. You can change video resolution in the app. However, the maximum video resolution depends on your phone’s camera.

My mobile can film in 4K and I find the settings and can now film in 4K even with the Go app. You must start filming to change resolution:

stormense8 Posted at 2018-8-2 09:46
It say; When recording video, video resolution is set at 720p in DJI GO by default. You can change video resolution in the app. However, the maximum video resolution depends on your phone’s camera.

My mobile can film in 4K and I find the settings and can now film in 4K even with the Go app. You must start filming to change resolution:

Then that's a great news then. Have fun using your Osmo.

stormense8 Posted at 2018-8-2 09:46
It say; When recording video, video resolution is set at 720p in DJI GO by default. You can change video resolution in the app. However, the maximum video resolution depends on your phone’s camera.

My mobile can film in 4K and I find the settings and can now film in 4K even with the Go app. You must start filming to change resolution:

Wait:
You started in 720 and changed during capturing a video?
Question:
This video you had on, during switching to 4k, that is 720p, right?
Did it change for the next video?
Or do you have 10 sec 720 and >10sec 4k?

S-e-ven Posted at 2018-8-3 03:04
Wait:
You started in 720 and changed during capturing a video?
Question:

Next Time Laps video was started in 4K.

stormense8 Posted at 2018-8-3 21:49
Next Time Laps video was started in 4K.

Thank you.
It was irriating to see the settings change to 4k, but the  time was going on in your video.
I would usually expect it to stop and restart, minimum.