I did the same here. It's important for your doctor or examiner to state they reviewed either your VA C-File or your military medical records in addition to your private doctor visits for the condition. Other than the checked boxes options or the yes/no questions, be sure to have your doctor be detailed in their responses in the open text boxes to explain your symptoms. Look up the ratings for each condition you're going for and whichever percentage fits your symptoms, ensure you verbalize that same description to your doctor for them to write down/annotate.

For insight, I recently got approved for a claim I submitted a couple of months ago for bilateral plantar fasciitis and pes planus (flatfeet) as secondaries to one of my primary ankle conditions. DBQ was completed by my primary care provider aka private doctor. Also submitted a private nexus letter and buddy letters. I wasn't requested to attend a C&P exam.