Cathay Pacific Shekou Lounge access arrangements confirmed as follows, and the first one's a doozy:

• Cathay Diamond and Gold members when travelling on any airline – yes, I double-checked this – any airline departing from Hong Kong. Matters not if it's Oneworld, Star Alliance, SkyTeam, Emirates or Etihad etc etc – as long as the Cathay Diamond or Gold member holds a boarding pass for a flight from HKG, they’re good to go
• First class and business class passengers only travelling on a Cathay Pacific flight (no partner airlines)
• Cathay Silver members and Oneworld Emerald and Sapphire members only when travelling on a Cathay Pacific flight (no partner airlines)