Cute video ... very calm/friendly chin (especially with his history).
You've put out a real smorgasbord of treats for him. (They should only have one or two treats per day.)
What all do you have there?
Looks like papaya
rosehips
maybe pineapple and yucca
... but, I see a
nuts ... please do not feed your chinchilla nuts, they can not properly digest nuts and fat builds up in the liver, which can eventually kill a chin. It's a common mistake many make and do not find out until it is to late for their chin.
Jo Ann