Getting ready for another trip to Singapore, and happened to take a look at their lounge access policy again. It looks like they've updated the rules (as of September 2023) and it seems to apply that United Club members now have access to KrisFlyer Gold at SIN. Definitely a welcome change, if I'm reading it correctly, for Silvers + non-elites with the membership

Footnote 10 on Star Alliance Gold now reads: Star Alliance Gold privilege applies to the Paid Lounge Membership United Club and Air Canada Maple Leaf Club.

https://www.singaporeair.com/saar5/p...nge-Access.pdf