Speaking from my perch, I think what might be needed is a "* Platinum" level equivalent to OW emerald for people in the 100,000 mile levels. That could provide some additional benefit for AC SE's, UA 1K's, LH SEN, etc. SK and TG don't have 100k milage levels, but I suppose they could create them, or award * Plat to qualifying members.

LH FTL's could then be upgraded to *Gold from there rather inadequate position right now as * Silver.

SQ's position on access to their SIN lounge seems to me to be churlish. However, they don't give access to their Krisflyer Elites, either. Their PPS program is strictly limited to P/J fare paying pax, and I suspect that they want to keep it that way.