Just a couple of points at this early stage:
The listing of available aircraft to add to the formation did not follow the sequence of my hangar listing.
It MAY be because I've re-named models so that, eg, all my DeHavillands are together, and not spread over CBFS DH80...de Havilland....DH114, etc etc, and perhaps "Traffic" lists by their original model names.
I decided to add 4 Venoms to "my" Venom, but could only see 2 of them on the ground, and in the air, a max of 4 all up. It was a horrible experience, as the external view was very shaky, like a badly tracked video. I remember posting this problem a few months back when flying a single aircraft around Barra. IIRC, things improved when I selected "Fixed Spot" or similar.
Then, of course, I tried Instant Replay, which only shows "your" aircraft, and that, too was un-watchable.
I'll try some less-demanding set up, using AI, not necessarily in formation.
I don't use a fraction of the things it can do Mike.. mainly the quick formation tool as you've seen but it will do much, much more 
