Dynamic rendering of instances

[birdm4n]

Hi everyone,
I was wondering how to do sth like the following three.js example in r3f:
https://threejs.org/examples/?q=webgl_buffergeometry_instancing

I am actually just talking about the slider on the right. I am looking for a way to set a buffer for the max number of instances but control how many are actually drawn.

My app has instanced boxes flying away from a starting point and I don't want them to appear all at once at the same position.
Basically like this example: https://codesandbox.io/s/g1s88
Is it possible to count up the number of rendered boxes in the beginning so they start falling one after another instead of all at once?
Thanks for the help!