RunCloud uses an agent to connect to your server. This agent is a lightweight application running in the background of your server to manage and monitor your server. By running the agent, you cut the problem with current server panel, resources usage. By running the lightweight agent, your server will use most of its potential just s if you were managing it manually using terminal.
If you are worrying about the connection between RunCloud Panel and your server, I can say that it is secure enough. By reading at their landing page, I found out the connection is encrypted using a secure 2048-bit key with SHA256 message digest algorithm. Each server will be given serverID and serverKey for authentication and if the agent is getting attacked by brute force, it will be blocked after several attempts.
If you are using RunCloud, you might be concerned about your data since RunCloud have file manager inside their SaaS panel. A few minutes after chatting with them, they tell me that they blocked all admin and super admin from seeing or modifying your files inside your server. They even said that they are not interested in your data since they provide the service to help manage the server, not to sell data.
The point is you have to trust them with your server. I even asked them about free-tier usage, do they take any data from that and they tell me they are not into data selling which they despise about it. “Your data is yours. By just peeking into it, we might broke the law and we don’t want to do that ever. We don’t want to know what is inside your server, your password, or what any secrets you may hide inside them because we are not interested at all. What we want is to help them manage their server easily. If they subscribe to our service, it is good for us. If they don’t, we have to find another person that is willing to use RunCloud’s full potential that will help us pay our server and our salary.”, they tell me.