The KLM forum regulars mention that Singapore Airlines sends its premium passengers to the Privium West Lounge,
They managed to negotiate access because the Aspire Lounge was just sad & embarressing,
even though at certain times they carved/rented out at the back a bit of private space for only SQ-customers with improved catering..,.,
Now that the Aspire lounge is being redone,
The choice for the Privium West Lounge seems logical because it is really the only other lounge left as option at AMS- NON/Schengen besides KLM's lounge 52 Skyteam
Last summer SQ had already sent in certain months their premium passengers there....
[or Otherwise Lee Kuan Yew would return back from the grave to take proper action & leadership]
(Privium lounges normally only accesible if one has a paid premium privium membership :
https://news.schiphol.com/schiphol-r...r-renovation/? )