Yes, I thought about the frame rate increase. But also realized that I can fire 10 rockets off a P38 (which leave smoke trails) with no perceptible frame rate loss to me. So then I thought they could use something similar to that. Don't really need the contrails lasting 20 minutes in the sky...just something to identify someone moving along at high altitude. Look at the speed of the movement in the sky (and on map) to figure out if it's a BUFF or not. Anyway, it's not something that ruins the game for me by not having them.