I think in general, the 'published' action can be considered an 'approval'. The question is, how do we control who has the authority to 'publish'? The Web UI today does not support any uploads outside of the coding environment, would be nice it would be supported. But for now, the only workaround is to include parameters that stores document urls in the user properties.
This sounds like a use case for the enterprise version of ClearML. In it you can set read/write permissions. Publishing is considered a "write", so you can limit who can do it. Another thing that might be useful in your scenario is to try using "Reports", and connect the "approved" experiments info to a report and then publish it. Here's a short video introducing reports .
By the way, please note that if the experiment/report/whatever is published, you can’t update it in any way after publishing.