Set resolution of AnimTrail driven by AnimNotify

I have a projectile that is flying through the air with an AnimTrail behind it. The AnimTrail is triggered by an AnimNotify on the animation.

Everything is working great except that I can’t figure out how to turn down the resolution or quality of the trail. It seems to be taking samples extremely fast… every frame if I had to guess.

Can I turn down the AnimTrail sample rate somehow? The spawn parameters in the particle emitter don’t seem to matter. Do I need to switch to using a Ribbon emitter instead if I want to tweak this sort of thing?

Using UE 4.7.3.