The timing, 6 hours over two days sounds standard. Sometimes with younger children they might spread over 3 days, some places cram it into one. I agree that just because there is a large spread between VCI and PRI this does not mean NLVD - It is hard for me to understand how a child can have a deficit if their PRI is actually in the high average range and better than 80% or more of the general public. With my son, I choose to think of his PRI as a relative weakness compared to his verbal abilities.
I disagree that scores in the average range rule out learning disabilities. The average range is very big - from the 75% to the 25% on most tests. Surely one would expect better academic skills from a person with and IQ above the average range than say the 25 percentile. While the discrepancy model shouldn't be the only way one can diagnose LD, if a discrepancy exists, it should be considered very carefully.
I like that he would look at EF and consider mood and sleep. I guess I would want to find out more about his concerns with a gifted program. Does he dislike them because they might exclude 2-E students (gifted with LD)? I guess I wouldn't take the comment at face value until I dug a bit deeper if I felt he otherwise would be a good match and comes recommended. If your goal is to enroll your child or keep your child in a gifted program and you find via your questions that he simply does not like them under any circumstance, I think you should move on as it is unlikely his recommendations will support your goals.