Hmm. I'm less confident that the explanation was a single developer testing something manually. We typically only block IPs in this manner when they are sending a great deal of traffic (a "ridiculous" amount in a 24hr period, hundreds of thousands of requests). For reference the block on your IP was added at the end of January, so it wasn't something very recent.
By chance have you ever used the ACME client "cert-manager" for a Kubernetes cluster? If you are certain it was your home rolled PowerShell automation that caused this block can you identify a root cause for why it would generate so much excessive traffic?