Not sure if this was / is already common knowledge (and perhaps I missed the memo), but apparently many international --> international transfers at GVA don't get access to the SWISS lounges due to airport layout

I just flew JFK --> GVA (on LX 23) and then onward to LHR (also via SWISS), and upon landing, I went through transit security and then over to the C gates, which is after passport control. However, the SWISS lounges are apparently before passport control, and I wasn't aware of this (not that I'd likely do passport control just to spend 2-3 hours at the lounge).

Was this always the case / common knowledge, or a more recent design flaw that's come to light?