Paired Endings - how do they work?

[nocturnal YL]

I hope bumping a 20-day old post is OK here. I just finished my first playthrough because I spent way too much time fiddling with menus and actually walking in the monastery instead of using the R button map.

I've been wondering about the same thing, and my first reference (https://h1g.jp/fireemblem/?クリア後に表示されるもの) said pretty much the same thing, except that A (if no A+ available) is treated as the same as A+. And I think that's probably not right, seeing how I've got Dimitri with A support with multiple characters and somehow ended with Flayn (who does have A+ with Dimitri, I think), who should be the last in the list among those with A support.

Now, I'd like to know if anyone has a more solid conclusion on how are the endings determined, and if there's any way to tell A+ from A, since I think the "Share a Meal" list shows only A+ for pairs with explicit A+ supports (or Byleth, who has potential S supports), unlike the internal B+ and C+.

Personally, I do wish to have some control over these pairings, since they affect what can be unlocked in the next playthrough. Intentionally holding off A support would mean the same A support cannot be unlocked in New Game+.

[ElissaApocalypto]

I'm wondering, does buying up S-Ranks in New Game+ affect this? I'm in a New Game+ for my Blue Lions playthrough and I'm playing male Byleth this time to get the supports I couldn't get playing female.

[UNLEASH IT]

Does it really matter though? I mean, this isn't awakening, there's no gameplay effect of marrying units together