Has anyone matched footage from the Sony FDR-AX100 and the DJI Phantom 4 Pro in 4K. Any suggestions on settings to match to two would be appreciated.

I have the AX100 and there's not a lot of customization available like on higher end cameras. I see you have Vegas, so if nothing else, use the Color Match feature in the effects listing. It works pretty good if your two cameras aren't too far apart. I've gotten "good enough" results when matching Sony and Canon video clips. The Sony was higher saturation and higher contrast, and Color Match helped bring it under control and more closely match the Canon look. Quick and simple.