Originally Posted by
weero
It is of much more negative interest to elites. As the US carriers allow for much higher limits than the Asian or European carriers do.
On SQ, the North America flights only allow for 3x50lb whereas UA and AC allow for 3x70lb.
Since this applies to all IATA airlines, I guess in your case then the best option would be to book SQ operated flights marketed by UA so that way you can have the 3x70 baggage (but 3-70lb bags is a lot for one person, no?) and then still enjoy the better flight with SQ, but I'm not sure how policies differ for flights that don't originate/end in US.