Delta keeps making these harder to use. Twitter team just sent me the following response when I asked them to check several flights on one day. I had a 3+ hour schedule change, so I was trying to find any routing where I could confirm the upgrades on the overwater flight (trip is to OGG).
"I can only check for upgrades on your ticketed flights. I show that at this time the upgrades are sold out on your flights. If you change your routing your entire airfare would need to be recalculated. Thank you. *TJM"