According to the book I have Elvis Day By Day that what you see on Elvisconcerts.com, which I think you was looking at the one I listed that I got from Christian. All of that is true.
March 30 1972 - RCA Hollywood studio ** Filmed with MGM film cameras
March 31 1972 - RCA Hollywood studio ** Filmed with MGM film cameras
April 05 1972 - Buffalo N.Y Hotel conference room ** Filmed with MGM film cameras
April 05 1972 (8:30 pm). - Buffalo, NY. ** Filmed using a mobile video camera
April 9 1972 - Hampton, VA. (2 concerts) ** Filmed with MGM film cameras
April 10 1972 (8:30 pm) - Richmond, VA ** Filmed with MGM film cameras
April 13 1972 (8:30 pm). - Charlotte, NC. ** Filmed with MGM film cameras
April 14 1972. (8:30 pm). - Greensboro, NC. ** Filmed with MGM film cameras
April 16 1972. - Jacksonville, FL. (2 concerts) ** + after show filmed with MGM film cameras
April 18 1972. (8:30 pm) - San Antonio, TX. ** Filmed with MGM film cameras
All of these was filmed according to my book. These was filmed by MGM. Now this doesn't mean the whole concert was filmed. This means that MGM filmed some of the concerts. MGM did filmed both Hampton Roads Concerts, Richmond concert, Greensboro Concert and San Antonio Concert, these was completely filmed by MGM. As for the others except for the March 30 and 31 because they were filmed in the studio. I mean the concert during the 15 day tour, some of these were filmed but they weren't completely filmed. MGM was their at Jacksonville, FL because we have the footage after the concert on either This Is Elvis or EOT Outtakes. This footage from Jacksonville is the buried in the beaver footage as it is known today. The Mobile camera footage can be pointed out in the EOT movie. During the dialogue that is before Can't Help Falling In Love and the beginning part of that song was filmed by the mobile camera. Now you might want to know how big is this camera. This used 8mm film and had a tripod that sit up on stage. Their has been rumors that MGM was their during Elvis' four performances at MSG. Well their is a picture from June 9 and you can see a mobile camera right up on stage. Is this the same one that was used during EOT? I don't know but it looks like the same one but other than that I can't say. But MGM was their during the whole time of Elvis' 15 day tour but they didn't film all the time.
I hope this answers in your question.