The Great Open Source Debate with Elastic, Gluu and GitHub 🎤 Oct 26

Question: Is there an option to set an entire rocketChat server to readonly?

Our management would like to switch to another communication portal. Therefore, I would like to know how I can switch an onPremise server to readonly in order to access the chat history, but at the same time prevent colleagues from actively using the chat to write. I have only found the following:

Is this really the only way?
Greetings