Short memo.

O2P in TP create particles from picked mesh at once.
So at once that they born at the same time, literally.

Because they share same age as value, you can’t use age parameter to drive anything.

As workaround you can use combination of “Eggtimer” and “Particle Age(enters group)”.
With “Particle Age(enters group)” you literally press the stop watch of “Eggtimer” and “Eggtimer” counts the time how long time has passed after entering the group for each particles.

Here’s the example of straight piping of age value to ValueToValue:
(which doesn’t work)

And here’s workaround with Eggtimer and Particle Age(enters group):

And here’s side by side comparison of them:

You’ll notice that one with age to ValueToValue seems to work in first several frames, but quickly you’ll see
the particles start to pop up at once.