I'm know that PA client definitely have some wireframe-related functions, may be when runned in developer mode. Is there some way to enable it's visibility?
Not sure how. The server dictates what is sent to to the client. You can't see through the fog if you're not given information on what's in the fog.
If wireframe was a specific function that would be available to consumers, then fog blocking wireframe outside of vision from rendering would be something that I would expect to see. But as a developer tool? I don't know how the system deals with fog. I didn't presume it as a given anyways, because I've played other games where wireframe did allow for intel past any smoke/fog.
PA is not working this way, or at least it's shouldn't work this way. Server should only send to client recon info which is available for him, this one of biggest advantages of client-server model. I'm need wireframe because I'm interested to check some performance drops issue related to planet geometry.