Thank you dw and WantFunBuyFun for the input on selecting only the first meal - confirming this is true both in PS and D1. The mid-flight snack and pre-arrival meal are served from front to back with no pre-selection. And there is no FEBO on international flights.
The meal selection link in the Fly Delta app stayed broken for my entire trip, and I never got the email either. Our pre-selections finally went through after chatting with the iMessage agents 4 times.. But once I found the right agent, the meal on the inbound flight was also selected at the same time even though it was 16 days away, way outside the normal 7-day window.

Photos below:
DL27 ATLICN Premium Select

Korean Braised Beef Short Rib, soy demi-glace, buttered rice, roasted vegetables, perilla green sauce; Mixed Greens, grape tomatoes, radish, blood orange vinaigrette; Olive Oil & Sea Salt Flatbread Cracker; Tiramisu

Three Cheese and Rosemary Pizza Twist

Cold Somen Noodles, sesame ginger scallion dressing, cabbage, green onion

DL26 ICNATL Delta One

Beef Tteok Galbi, ginger garlic sauce, red onion, Shiitake mushrooms, grilled asparagus; Korean Cod Soup; Banchan, white kimchi, sweet chili shredded squid, stir fried crab meat and egg; Appetizer, shrimp and mushrooms with garlic

Ice Cream Sundae, Biscoff crumble

Soy Chicken and Kimchi Dumpling, potato, chopped cabbage

Shrimp Congee, egg roll