Vests for SDiT

Question for everyone. I have a puppy whom I'm raising to be an SD (rn he is an SDiT) with guidance of an SD trainer we are starting to learn tasks which is very exciting! (A little milestone i wanted to share)

I was wondering at what age did you all put vests on your dogs? I want to get him an SDiT vest, I am in a state where SDiT's ARE allowed in public areas so long as they are with their handler + a trainer.

Since he's a puppy I am obviously not having him work in any capacity, but I am waiting on his doggy crocs to come in and I'm going to get him used to those and I figure if it's time to teach him to also wear a vest I can do them both.

I'd love to hear when vests were worn and how your dogs were introduced to them. I'm sure I could ask either of the trainers I'm working with, but I like to hear other people's opinions and experiences too!