UAS Topo with RCRUS DJI S800

I'm checking to see if anybody else is using the DJI S800 for Topo and Boundary Surveys. I'm flying around 5,000 feet and generating 1'foot and 2'foot contours for topo and I'm getting some errors from multi point resections from the DJI's ground stuff...does anybody else have this kind of problem or am I using to many ground points for my DTM's...? or do I need to go to 20,000'feet and align projection and scale to the DTM's because of Resolution issues..that Im not aware of yet??? thank you all for your help

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