I don't advise well checks, they can stress the chin out and create a problem (stress induced but also exposing the chin to sick animals at the vet). Your best bet if you want to actually see a vet to make sure they know what they are doing is do a meet and greet appointment, without the chin, so you can ask questions. It is very important to find a chin knowledgeable vet before you need one though.
Also most of what a vet would do on a wellness check you can do just as easily, and less stressfully at home. Weigh the chin (in grams since they are so small), look over the fur, feel for any bumps or lumps, check the feet for cracks or flakiness, check the front teeth, etc.