I always wished there were a way to slave the rider's views to the pilot's (yeah, there's film for this, but I'm talking about as it happens) so the rider can get a sense of what the pilot is looking at as the engagement unfolds, especially in multi-plane environments.
it's always polite to ask before using the .join command because unless the player has .showjoin 0 the request will show as a big box (press button to accept) instead of a text buffer request (.accept) the box can block views if an unexpected request shows up.
Unfortunately you cant see when your pilot is shooting which is the biggest issue I have, aim.
It is useful to see how someone else approaches the fight, the angle and timing of their merge, how they react to the maneuvers of the other planes and so on. But to see the lead they use and such no good.