Thank you for your question. You have already hit the nail on the head so to speak. While we aren't aware of any major issues to look out for on the beta, it is still a beta and issues may arise. Also, for clarification since I don't know if you mean the Covenant Eyes beta or the iOS 15 beta I will say that installing the Covenant Eyes beta on a current operating system would be fine but my developers do not recommend installing any version of Covenant Eyes - current release or beta - on the iOS 15 beta.
If there is anything else that I can answer please don't hesitate to reach out. Thank you and have a great day.