Need some advice, wasn't sure if I should put it here or not.
Looking for upgrade capabilities on Star Alliance flights, with a large stockpile of points on both Singapore and United. One person is Singapore Gold, and the other is United Premier Platinum, both looking to requalify on their airlines this year. Looking to buy premium economy or full fare economy from LAX to France early next month (can fly from New York or land somewhere else in Europe for cost/upgrade availability).
Is it best to book a singapore flight and upgrade iwth singapore points on both flights, and have one credited to united? Or book both on a United codeshare and upgrade with united points on both? Is there any routes I should look into for better chance of upgrade?