I Just did a search and found one date available with what you're looking for. Nov 5, 2024 on SQ11 which is usually saved for the 777. It shows it's LAX - SIN but in reality you have to disembark the plane in NRT for an hour or so then re-embark. I tried to add a stopover but that specific segment disappears. Atleast it's still 87.5K points.
Thanks for doing the search! Interesting that the result won’t show the NRT stopover or let you book it, but yeah it’s essentially that route. I wonder why they’ve blocked off the stopover option…