Yes, that is odd route. I don't know of anywhere else where the F fare is only about 30% more than the Y fare, and no more than a nice meal at a restaurant. If you know of any, do share!

Timing is everything. I was at the SQ SIN lounge from midnight to 5:30. Just me and two other people. The MH KUL lounge might have at 6 or 7 other pax. Compared to midday there or at the RCC's, you have a lot of privacy.