There are two rate limits to consider when using the Media Rights Service to reach out to Instagram users for consent to use their media outside of Instagram:
Instagram's Rate Limit: Instagram imposes a rate limit on comments that's limited to 60/hour for each user. Attempts to issue media rights request beyond this will generally result in an error message indicating that it was rejected by Instagram.
Candid's Rate Limit: Candid imposes a daily rate limit of 25 rights request for new accounts. This limit is flexible and can be eased gradually as the brand builds more familiarity with the service.