Experimental gismu and cmavo are clearly denoted as such, so there’s no reason why experimental lujvo and fu'ivla aren’t.
Maybe this could be automated?
A lujvo is called “experimental” if at least one of its rafsi is derived from an experimental gismu or cmavo.
A fu'ivla is called “experimental” if it is in stage 3 and the used “topic rafsi” is derived from an experimental gismu or cmavo.
Experimental gismu and cmavo are clearly denoted as such, so there’s no reason why experimental lujvo and fu'ivla aren’t. Maybe this could be automated?
A lujvo is called “experimental” if at least one of its rafsi is derived from an experimental gismu or cmavo. A fu'ivla is called “experimental” if it is in stage 3 and the used “topic rafsi” is derived from an experimental gismu or cmavo.