Another datapoint- multicity itinerary, XXX-oSIN-JFK//EWR-oSIN-YYY.

A months old schedule change on SQ21 (EWR-SIN) booked for August, which we weren’t properly informed about, was enough to get a rebooking onto the ‘unwanted’ SQ25(the direct JFK-SIN), for -3days, and, negotiate a free change for SIN-YYY for taking the ‘unwanted’ flight. That sector was rebooked to way way beyond 7 days (& hey- 250 bucks a pop times 4 pax..).

SQ25 only had Z available with any PoS, we were in U. While not quite as straightforward as with US carriers, a pretty decent outcome.