Kill Height imprecision in Cascade

Hello guys,
I’m trying to have particles falling onto the ground and spawning another emitter with an Event Generator.

While that is working, to know if the particle has hit the floor I’m using an Actor Collision. But I’d like to use the Kill Height solution, since this particular effect has a known floor height in world space, and I thought that this would be less costly than using actual collisions.

The problem is, there seems to be some imprecision with the Kill Height ?
The particles that falls onto the ground start kinda high (like 1000 units) and falls with a Const Acceleration of -1500, so they hit the ground with a certain speed.
This is not a problem with the Actor Collision, but the Kill Height has the particles dying a bit late (see attached capture)
The same issue happens with Kill Box.

The issue is being made more apparent the faster the particles hits the Kill Height.

Is there a way to fix this ? Have I missed something, or done something wrong ?