This is only a spur-of-the-moment thought, so it is not very in-depth.

Much like how we have the trainer-divebombing site available in the TA & offline to practice jabo runs on various targets, could there be perhaps a
training LEAD site available to practice & refine leading aerial targets from ground & sea-based positions (field guns, vehicle AA, and various ship AA)? It would have to be coded so that one can select the target aircraft, and a corresponding lead (training) site would appear ahead of it according to velocity, altitude, & trajectory. It would also need to disappear when the target is no longer in effective range.
This is only an idea exclusively for training. Am I nuts?
