When do chins stop growing?

I was just curious when chins top out and stop growing.
Julio is a 520 grams at 1 year 6 months.
He looks so little compared to other chins I've seen, but he is a good little eater / pooper.

There was also another post discussing the benefits of getting an adult chin vs a baby because personality is more established.
At what age would you say that happens?

My chin is a very sweet little guy.
He will still occasionally peep his treats / attention.
Do adults continue to peep or is this still a "baby" thing?

How long does puberty last in a chin?