I am curious about a couple training extensions that might be cheap to implement.
First, I like the idea of "repairing" a used target by adding a sheet of paper to the rear of a shot-up target to force the shooter to call their shots rather than getting any information on the target while allowing for accountability.
Also, I really want to know what kind of material would be necessary for a reactive target. Think one of the 3d human head & torso targets with a clump/bag/balloon of red material placed where the heart and brainstem would be and only call the target down when they're hit and the shooter observes it correctly.
Abner Miranda does something like that with small(ish) steel targets on 4x4s with a protective target in front of it (to reduce / redirect spall) that obscures the actual target zone and allows the whole target to fall after a few quick shots on the target zone but not near misses.
All seem like a lot of fun and valuable for different kinds of training.