Apparently the app 'AZ Camera' allows for a manual mode when taking selfies. On their page they claim
"AZ Camera is the best FREE camera app that utilises Camera2 API from Android to support RAW format (DNG), manual focus, manual shutter speed, manual ISO, manual white balance and exposure compensation. The manual controls are available in both photo mode and video mode, for both rear cam and front cam."
For people having trouble with their selfie cam overexposing or changing the iso too much, maybe this might help? Has anyone tried this? I don't know if it will work with the V10, but thought it might be a solution if it does.
I'm glad this thread exists now, so far the pictures have been really helpful