Regardless of how you were going to end that question, the answer is the same. It is critically important not to use an IP Address. Wisetail is a cloud-based platform, and our endpoints can & do change in an irregular, non-predictable manner.
If you utilize an IP Address rather than a Wisetail-provided domain name for, well, pretty much anything, it becomes a matter of when -not if- your system will break. This is true whether you are talking about datafeeds, whitelists, or any other part of our product.