Automating additional addresses for customers?

Automating additional addresses for customers?

Hello,
For customers, we can have a billing address, a shipping address, and additional addresses as well now.

I have two questions.

1. How many additional addresses can one customer have, is there a limit?

2. The API documentation doesn't contain any mention of updating additional addresses. Is the API field missing from the documentation? It would be great if addresses could be added via automation from other modules.