You’re probably right re: 15s, as much as I don’t want it to be. My concentration on 7s has been driven by the dire need for referees willing and fit enough to do college 7s in the spring.Bluntly, they're not going to invest in you for 7s, knowing what I do about selections for the Stuff That Matters.
In your shoes I'd concentrate on 15s.
For a small fee - regaularly posting "like" to all my posts, for example- I can take a look at a couple of videos for you.
Feel free to watch the above game and critique - it was the only meaningful 15s game I’d done since early November, so it’s the only recent tape I got.