It was early afternoon. They've been swapping out which characters have actual meet and greets over in the stage area, so I'd probably ask a CM working with any Marvel character in the morning (like Captain America or Spiderman) and see when and where they'd recommend that you be to hopefully see them. I find that when you say things like, "We have a real Dr. Strange fan here and are hoping to have a chance to see him today; do you have any tips on how to make that happen?" they can be pretty forthcoming, especially if you are kind and seem enthusiastic rather than entitled.
The app has been really glitchy with character times lately (on Tuesday, we went to meet Pocahontas at 10:40 during a listed "10:35-11:05" set and she was leaving. I asked a handler when she'd be back and he said, "I'm not quite sure, but you can go and meet Moana in Adventureland in five minutes!" I nicely said something like, "Thanks so much, but we're specifically hoping for Pocahontas because she's my niece's absolute favorite and the app was inaccurate so I'm a little nervous - it says 11:35, but it also said she'd be here until 11:05." He said, "hold on, let me go and check for you, stay here for a minute," then he disappeared behind the wall and came back and told me she'd be back at 11:05 and showed me where... then he said, "the app keeps updating with other days' times, so it's been causing a lot of problems lately." Soooo, take that how you will, but I'd be checking with a CM if it's someone you really care to see. The superhero CMs will be the best-informed about the other superheroes.