I hope you are well.
Great question, In this situation I note that you may be able to avail of a self service solution. As this is for 3 different accounts, the user performing these License Key Rotation will need to have either Owner permissions or Full Admin permissions on the account.
As we’ve started offering the ability to generate secondary license keys, also known as ingest keys , using Nerdgraph. For more information on that process, check out this article. Something to note about using these ingest keys is that in the event you need to regenerate your keys in the future, you would have the ability to do so yourself!
I hope this provided help and guidance, please feel to let me know if this worked. Any additional questions are always welcome!