I have no knowledge of outstations, but I can assure you, no *A gold in Y/M will get into the SKL at SIN. C class pax only is strictly enforced.
Yes, but what is your point?
Did I say anything else?
My point is that SQ is more strict in access policy for SKL at outstations, e.g. at SFO.
I've only come across one report where the LH Senator Lounge refused entry to a *G cardholder with departing flight on a Star Alliance carrier - at MUC, when departing on TK. However, we have not received a confirmation on that incidence.
However, the fact that SQ SKL is turning away *G cardholders (departing on a Star Alliance flight) outside of SIN, is well documented here at FT.